Funny you mention this.

My buddy had an '08 M3 coupe that he bought brand new. Not only did the dealership not care about performance mods/etc., but when he went for service they would ask him what track he was planning on going to and would set the car up based on the specific track. Yes, they ASKED him if they could set up his car for the track...warranty claims were never an issue.

Fast forward to last Fall, he sold the M3 and bought a barely used (~10k) STi Sedan from a Subaru dealership. Turbo goes - they replace it but don't do a proper job and leave the lines loose...coolant and oil everywhere. Not to mention they gave it back to him and said 'sorry, but it won't make boost and we don't know why. All he did was reset the ECU and it worked fine.
A few weeks later - engine starts going...he takes it in and gets a call the next day saying that he's not covered because under the dash they found a wire harness for a Subaru aftermarket boost gauge (in the US it is a dealer-installed option - all Subaru parts). The car was completely stock otherwise and there was no gauge actually installed. The car had ~12k on it at this point.

He called Subaru Canada, the BBB, etc., etc. to no avail. He was considering litigation but decided to say 'screw it' and is doing a fully built engine, aiming for ~500-600hp.

I guess my point is to say, at Mitsubishi and Subaru, the Evo and STi (respectively) are 'the rarity'. Their bread and butter are the cheaper cars - lancer/impreza/outlander/forrester/etc. - or at the very least, not high performance vehicles. Whereas at a BMW dealership an M3, although expensive, is not anywhere near their most expensive car (although it ain't cheap) yet they still provide you with over-the-top service. They sell the M3 (and the M cars in general) as high performance track beasts - just like Subaru and Mitsubishi - but they actually back it up with the service one expects. This applies to Mercedes/Porsche/Audi/etc. as well.Why do you think they're getting rid of the Evo? It's not a market they care about.