[Iamlemon]

Hello guys and gals, my name is Victor and I am developing a rear seat delete kit for my M2 Competition. My process for developing it began when the only rear seat delete kit I could find was either grossly overpriced ($4-6 thousand USD) or made of flimsy plastic that bent instead of supporting the car. I wanted a kit that kept the rigidity of the car, was lightweight, all while blending into the interior, and even adding an OEM+ look to it.
That said, I have made some decent progress on the kit. The models for the metal underlying sheets have been measured and 3D scaled. This took about 2-3 months to do because of the complexity of the sheeting required. The sheets not only have to curve around a variety of surfaces, but also have the best fitment when at an incline. For example, the "flat" bottom sheet connects to the front at a lower elevation than it does at the rear, introducing a third dimension that I had to work with.
I have also completed a pressure test using a hydraulic press on a pair of scratched-up rear seats I found on eBay. This destroyed the seats but allowed me to figure out what pressures they were designed to handle. I compared the eBay OG M2 seat to mine and found that the Comp seats are the same, which indicates that the kit would work on an OG M2 as well. Given the information, I went to a machine shop to ask for suggestions on the metals I should use. I ended up deciding on titanium as a lightweight, rigid, and strong material that would be optimal for my application. I have sent over the models I had built last Monday (12/20/21) for them to see if there would be any problems with creating the sheets in-shop.
I have sourced the materials codes that BMW uses on their Alcantara as well as their orange and blue stitching. I plan to wrap the titanium sheets in stitched Alcantara to match the door panels the M2C comes OEM with. Heat treating the titanium is also an option for a different look, however, I do not think I will personally head down this route. I have subsequently found sellers for the fabric and stitching that will be required and will purchase the required parts as soon as I know the models work with the shop.
I plan to first implement this kit into my car and then possibly make a few more if there is interest in it. My Instagram is @8mpg4me if you want to see videos and images on the process through my stories firsthand as the project develops. There is plenty left to do though, and below you will find an updating list/roadmap of what has been completed and what remains.

List:

- Remove backseats (Complete)
- Purchase backseats for pressure testing (Complete 11/13/21)
- Create a physical model for metal plates (Complete)
- Pressure test rear seats (Complete)
- Create a 3D model of metal plates (Complete)
- Choose metal material (Complete - titanium chosen)
- Source codes for fabrics and find seller (Complete)
- Verify 2D sheets/corners are able to be cut by a fabricator (Complete 1/19/22)
- Find out the required thickness of titanium sheets based on pressure requirements (Complete 2/03/22)
- Figure out link/connection to be used for bolt-in of kit to the car (Complete 2/04/22)
- Verify 3D sheets/corners are able to be cut by a fabricator (Complete 2/05/22)
- Begin titanium sheet manufacturing (In Progress!)
- Apply rubber gloves to corners and connection parts
- Order fabrics and fabric glue
- Stitch fabrics as needed/desired
- Wrap titanium sheets in stitched Alcantara
- Install

As the process continues steps may be taken out or more steps may be added.

For those wondering why I am doing this project from an objective point of view: Weight reduction, lower center of mass, more trunk space, more front storage space, and actually MPG. The car MPG has raised significantly with a lightweight exhaust, lighter wheels, and no rear seats. Last week I made the trip from LA to SF on the I5 and averaged 27.6 MPG running on the stock tune and cruise control set to 69 MPH (nice). The removed rear seats weigh a total of 67.5 lbs (roughly 2% of the weight of the car). From a non-objective point of view, I think a nicely made rear seat delete looks awesome. Let me know if you have any questions/concerns or even suggestions. Constructive criticism is welcome. Again, the kit is primarily for me but I am happy to make a few for those who like the finished product on my car.

[M Fifty]

Have you considered just removing the rear seat backs? A few bolts, 10 minutes and a surprising amount of weight removed. Quickly reversible too, so useful for trackdays and similar.

[Iamlemon]

Originally Posted by M Fifty

Have you considered just removing the rear seat backs? A few bolts, 10 minutes and a surprising amount of weight removed. Quickly reversible too, so useful for trackdays and similar.

Yep! As I said, I have already removed the seats, and I am doing this not only to reduce a lot of weight but to also have the compartment where the seats were removed usable for storage while looking OEM+. The fuel pump mechanism is under the thin black tarp that is left over from a rear seat delete, and if I wanted to put a toolbox, tires, or really anything else in there like a suitcase or bag, I would be scared of damaging the pump mechanism and any flex-fuel kit attached to it. Additionally, there is exposed electrical wiring on the sides of the car with no seats there, and I would like to cover that up as well.

[F87source]

Very interesting, subbed for more. I would also be interested in purchasing a kit like this - because like you said the alternatives are grossly over priced.

[ndyvidual]

Originally Posted by F87source

Very interesting, subbed for more. I would also be interested in purchasing a kit like this - because like you said the alternatives are grossly over priced.

Agreed and also subscribed.

[m2cWW]

Interested!

[booya_45]

I’d be down to purchase something as well once I see the final product. Good job taking this project on!

[ebisu8]

Pretty cool idea. Is what you're building similar to this made by SLON?

[(K)]

That's so simple yet so clean and functional.

Looking forward to your finished product, OP

[F87source]

Originally Posted by ebisu8

Pretty cool idea. Is what you're building similar to this made by SLON?

Wow that's nice! It's probably expensive though.

[TargaM2]

Subbed & interested in purchasing a kit once completed.
I have 1 piece race seats fitted, so no access to rear seats anyway, however I want a delete kit that's oem looking before I remove the rear seats.

[Got f1?]

Originally Posted by Iamlemon

Hello guys and gals, my name is Victor and I am developing a rear seat delete kit for my M2 Competition. My process for developing it began when the only rear seat delete kit I could find was either grossly overpriced ($4-6 thousand USD) or made of flimsy plastic that bent instead of supporting the car. I wanted a kit that kept the rigidity of the car, was lightweight, all while blending into the interior, and even adding an OEM+ look to it.

Very interested!

[KevinC]

"Exceptional increase in torsional rigidity"

Really? How much is "exceptional"? Have they even measured the difference somehow? If so you'd think they'd provide the figures.

[F87source]

Originally Posted by KevinC

"Exceptional increase in torsional rigidity"

Really? How much is "exceptional"? Have they even measured the difference somehow? If so you'd think they'd provide the figures.

it's also almost $2k USD, so imo I rather just get a roll cage.

[to_riffic]

Originally Posted by KevinC

"Exceptional increase in torsional rigidity"

Really? How much is "exceptional"? Have they even measured the difference somehow? If so you'd think they'd provide the figures.

nam3forums on the E46 M3 side had figures and it looked to be a solid 28% rigidity improvement. That's pretty damn solid in my book. Downside is that once it's in, no more passthrough...

[mike@x-ph.com]

Sub'd

[Shadowfax028]

Originally Posted by mike@x-ph.com

Sub'd

Any pictures?

[Iamlemon]

Hey all, I am very glad so many people have taken an interest in my project! As you have maybe seen, I have been updating the road map as pieces of the project have been accomplished. The project is at the final verification stage and once it passes, all that will be left is a fabrication. The actual titanium cutting and punching will be done by a shop next to me and all the fabric work will be done by hand. Hopefully, there is about a month left assuming no hiccups in the plans. Let me know if yall have any questions. The final weight is estimated to be around 18 pounds (about 15lbs for no Alcantara and just bare or heat-treated titanium), meaning the OEM seats are 375% (at minimum) heavier than the to-be titanium kits.

[F87source]

Originally Posted by Iamlemon

Hey all, I am very glad so many people have taken an interest in my project! As you have maybe seen, I have been updating the road map as pieces of the project have been accomplished. The project is at the final verification stage and once it passes, all that will be left is a fabrication. The actual titanium cutting and punching will be done by a shop next to me and all the fabric work will be done by hand. Hopefully, there is about a month left assuming no hiccups in the plans. Let me know if yall have any questions. The final weight is estimated to be around 18 pounds (about 15lbs for no Alcantara and just bare or heat-treated titanium), meaning the OEM seats are 375% heavier than the to-be titanium kits.

How much do you anticipate these things to cost?

[Iamlemon]

Originally Posted by F87source

How much do you anticipate these things to cost?

Not exactly sure just yet, but that info will definitely come in the near future. Hopefully, it would be much cheaper to make than the RPK stitched alcantara kit which retails for around $5-6k USD. I have gotten a few messages about people interested in buying the kit I make, so in case the titanium option is too expensive I can also go down the route of cheaper, rigid, lightweight metals.

[jeff4598]

When i put 80 lbs of salt in trunk for snow traction the car handle MUCH better on clean asphalt. I think F?R balance is more important than toital weight.

[F87source]

Originally Posted by jeff4598

When i put 80 lbs of salt in trunk for snow traction the car handle MUCH better on clean asphalt. I think F?R balance is more important than toital weight.

Having good suspension can help off set some of the negatives of the weight balance being shifted forward but yeah balance is pretty important. However removing rear weight allows you to add other things back there like a cage or rear wing.