[NPTM]

I’ve done a ton of searching on this, and while I know BMW CF roofs have many issues, I can’t find any that look quite like this. It’s happening in two spots, both where the CF roof meets glass (up front and out back). No change in texture / feel, just this cloudy / foggy wavy look. Doesn’t seem to be moisture. Thought it could be clearcoat lift, but doesn’t look like the other photos I have seen around here. Hard to see in certain light but when the sun catches it just right, it’s as visible as the pics below.

Car has PPF, but not on roof…albeit she’s been garage kept her whole life and only 3.5K miles so barely any time in the sun. I’m going into BMW for the annual service in June and I’ll mention it to them then, but doubt anyone there is going to have a real resolution for me.

Any thoughts? Thanks all!

[inTgr8r]

Sorry you have this issue.
It's hard to fathom that BMW still can't get CF roofs right...

[NPTM]

That’s as bad as it ever looks - in most lighting you can’t see anything, but when the sun hits it just right, you do. Does not look like the issues I see in other posts, so just wondering if anyone else has this and what they think it is / what BMW has told them…thanks!

[chris719]

Originally Posted by inTgr8r

Sorry you have this issue.
It's hard to fathom that BMW still can't get CF roofs right...

This is a unique roof compared to the other BMW CF roofs. Those don't really have problems other than what results from physical or UV damage. This one, who knows.

[///MPhatic]

Originally Posted by NPTM

That’s as bad as it ever looks - in most lighting you can’t see anything, but when the sun hits it just right, you do. Does not look like the issues I see in other posts, so just wondering if anyone else has this and what they think it is / what BMW has told them…thanks!

I have a friend that does quite a bit of carbon. He says he thinks it was a manufacturing defect caused by not enough heat that took a while to make itself known (his best guess).

I positively hate that BMW can't get CF roofs right (not a shock, few manufacturers do, and even they don't last forever), as it's one less thing to dream of having.

Should be covered under warranty I would think.

[chris719]

Originally Posted by NPTM

That’s as bad as it ever looks - in most lighting you can’t see anything, but when the sun hits it just right, you do. Does not look like the issues I see in other posts, so just wondering if anyone else has this and what they think it is / what BMW has told them…thanks!

Most examples I've seen like this are on bike parts. It could be the clear separating from the epoxy/resin. Not sure. I also doubt it is UV because it's in areas of stress and typical UV induced clearcoat failure on a roof begins more toward the middle.

[NPTM]

Awesome thanks for the input - agree that it doesn’t look like UV. Manufacturing defect without doubt, question is…what the heck is causing it exactly. Luckily two of my buddies are BMW techs so any repair would be done (or at least supervised) by people I trust and respect, but still a tough call - if it’s the clear separation issue, I think that can be repaired and that’s much more appealing to me that swapping the roof, which sounds like a nightmare. If this issue was purely cosmetic (and not structural) I’d almost consider not doing that even if covered…

I also wonder if the heat issue you reference above is what causes the clear separation, OR if that results in something different…I’m not sure…

Thanks for any and all insight guys!

[bruiser135msport]

Hi
I’d be taking into your nearest Bmw Dealer sooner then later for a warranty claim .

I would not leave it until June next year .

Out of interest what month and year of production is your Cs ?

Just my two cents worth !

All the best
Cheers
Bruce

[NPTM]

Originally Posted by bruiser135msport

Hi
I’d be taking into your nearest Bmw Dealer sooner then later for a warranty claim .

I would not leave it until June next year .

Out of interest what month and year of production is your Cs ?

Just my two cents worth !

All the best
Cheers
Bruce

Yes car is in warranty through next year and wanted to see if it got worse over time or stayed same - but not going to sleep on this. Not sure on production date but will look into it.

Most notably to me, no one is raising their hand saying they have this too - so doesn’t seem like some mass production issue, but we’ll see…

[chris719]

Originally Posted by NPTM

Yes car is in warranty through next year and wanted to see if it got worse over time or stayed same - but not going to sleep on this. Not sure on production date but will look into it.

Most notably to me, no one is raising their hand saying they have this too - so doesn’t seem like some mass production issue, but we’ll see…

There are so few of these cars so it's hard to say. These roofs were all flawed in production and BMW tried to hide it, but whether that flaw leads to your issue or other kinds of failure is unknown.

[NPTM]

I hear you on that…no matter what, will keep you guys posted on what BMW says. Sure I’ll get run around for a bit and not sure I’d want to go through the replacement process if this is merely cosmetic, but we’ll see…thanks all!

[bruiser135msport]

Sorry but not true and does not reflect the facts :

“There are so few of these cars so it's hard to say. These roofs were all flawed in production and BMW tried to hide it, but whether that flaw leads to your issue or other kinds of failure is unknown.”

In Australia (with a very harsh climate) none have failed or showed floors : and we are lucky in that they were all last production runs and Bmw AG had plenty of production practice .

Even on these forums we have a had (very) very low failure rates .

To state every CF Roof was flawed is false . It is true that CF Roof manufacturing requires very high standards of production and quality control .

Where there have been failures BMW AG has honoured every warranty claim and carried out very comprehensive and complicated repairs and/or replacement.

Cheers
Bruce

[NPTM]

“Flaw” and “fail” are two different things, and I think folks are more so saying the flaw rate is super high, which is hard to argue with if you look across BMW models with CF roofs.

The CS “weave issue”, albeit purely cosmetic, was viewed by most as a flaw…doesn’t bother me, I actually kind of like the uniqueness, but still technically a flaw from a production quality standpoint. I know now all CSs have this, but most do.

And I’m sure BMW will eventually help me find a solution - the question is, do I do it if this is purely cosmetic. The thought of some body shop pulling my entire interior apart to swap a roof is brutally painful to me…but redoing the clearcoat, I’m ok with that. Well see, stay tuned!

[///MPhatic]

Originally Posted by NPTM

I also wonder if the heat issue you reference above is what causes the clear separation...

It's most likely not external heat that caused the separation/delamination, it's inconsistent heating while it was being manufactured that caused the issue. Even if the car never saw sunshine this would appear over time.

[NPTM]

Originally Posted by ///MPhatic

It's most likely not external heat that caused the separation/delamination, it's inconsistent heating while it was being manufactured that caused the issue. Even if the car never saw sunshine this would appear over time.

Now that would make more sense, since the car has been garage kept its entire life.

Not to give you home work but if you happen to talk to your buddy again, mind asking him if this is merely cosmetic, or any structural risk? Does he think it will get worse over time?

Thanks so much, appreciate it!

[NYNick]

This makes me want to check my 5700 miles garage queen closely.

[NPTM]

Originally Posted by NYNick

This makes me want to check my 5700 miles garage queen closely.

Yes it’s actually hard to see if the light isn’t catching it perfectly - my pics make it look glaring, it’s not, you really has to look for it and catch it just right. We’ll see what BMW says nonetheless.

[F87EVO]

Originally Posted by bruiser135msport

Sorry but not true and does not reflect the facts :

“There are so few of these cars so it's hard to say. These roofs were all flawed in production and BMW tried to hide it, but whether that flaw leads to your issue or other kinds of failure is unknown.”

In Australia (with a very harsh climate) none have failed or showed floors : and we are lucky in that they were all last production runs and Bmw AG had plenty of production practice .

Even on these forums we have a had (very) very low failure rates .

To state every CF Roof was flawed is false . It is true that CF Roof manufacturing requires very high standards of production and quality control .

Where there have been failures BMW AG has honoured every warranty claim and carried out very comprehensive and complicated repairs and/or replacement.

Cheers
Bruce

Actually Australia’s harsh climate might help the roof. Same here , i live in a similar climate country , and i believe the problem with the roofs might be the delamination issue comes from the cold. If you have the car under 40-45 degrees the laminate on the roof becomes one with the roof. Just like you have to heat a car once you ceramic coat it. The roof under temperatures around 40-45 degrees and with sun might reach very high temperatures and help the roof become stronger with the laminate etc.

Its just specculations tho , but every case ive heard , its usually from cold climates. And it usually starts slowly from the day delivered but it shows the signs later. So this might be the issue , the laminate its fresh and with cold weather it might cause this issue.

I took my car in August 2020 , it was easily 40 degrees celsius + , sunny until mid November, and i drove it at least 6000km since November. I heard a case that happened while parked in a garage during winter and after few months stored , it happened.

So maybe this makes sense , but again its just specculations. Time will tell , but hey its not the end of the world, if it happens its ok, ill just fix it.

The cases arent many , thats true.

[///MPhatic]

Originally Posted by NPTM

Now that would make more sense, since the car has been garage kept its entire life.

Not to give you home work but if you happen to talk to your buddy again, mind asking him if this is merely cosmetic, or any structural risk? Does he think it will get worse over time?

Thanks so much, appreciate it!

The white is actually dust created by micro-crack delamination, meaning as the fibers pull away from the resin there is resin-crack dust left in the gap. This will absolutely propagate/get worse over time, and will cover all areas that were unevenly heated/bonded/cured. The worst part is that the delaminated parts will start to tug on the correctly cured parts and cause them to fail over time as well, so it's just a matter of time/heat/cold/movement until you have it all over. Beyond that it'll get worse, so the whole roof won't just look like that spot, it'll look worse.

How long that'll take is anybody's guess.

[NPTM]

Understood - all super helpful, definitely going to get BMW on the hook for a fix pre warranty expiration. Will keep you guys posted thanks for all the advice!

[chris719]

Originally Posted by bruiser135msport

Sorry but not true and does not reflect the facts :

“There are so few of these cars so it's hard to say. These roofs were all flawed in production and BMW tried to hide it, but whether that flaw leads to your issue or other kinds of failure is unknown.”

In Australia (with a very harsh climate) none have failed or showed floors : and we are lucky in that they were all last production runs and Bmw AG had plenty of production practice .

Even on these forums we have a had (very) very low failure rates .

To state every CF Roof was flawed is false . It is true that CF Roof manufacturing requires very high standards of production and quality control .

Where there have been failures BMW AG has honoured every warranty claim and carried out very comprehensive and complicated repairs and/or replacement.

Cheers
Bruce

No, you're full of it. Sources from Garching told 2 forum members here back in late 2019 that that these roofs were all flawed and it was too late to get them all replaced before production. The weave is kinked and they tried to mask it by tinting the clear and doing multiple layers. The kinked weave would normally have condemned these parts. You seem to have no clue how manufacturing works either. They likely received the entire lot from the manufacturer at once or close together otherwise they would have rejected the parts. It's assumed the defect is cosmetic only, but only time will tell.

[bruiser135msport]

Oh dear oh dear !

I didn’t say you were full of it sir !

I said your wrong (a very different statement) and a little decorum on these forums would be appreciated .

Do you actually own a M2 Cs ?

Mate I’m in the aerospace industry and deal with this on a daily basis !

Have a nice day