The sum of the whole would need to be more than it's parts, meaning in several years would picking up a used "regular" M2, doing an s55 swap and corresponding brake, suspension, interior mods be cheaper than a sky high priced, too afraid to drive it M2 GTS? Used S55, lots of work done yourself, etc, obviously not buying a new crate motor.
I love the idea, but as many have said it would end up being a collector car, rather than the ultimate fun track toy it is portrayed to be.
In the US if it were priced around 90k with GTS interior, ccb, competition pack S55, etc... Ya I'd probably buy it.
