^ I agree 100%
Having warranty issues with both MB and BMW recently, there is no clear yes/no coverage when out of warranty. It's all a crapshoot (no pun intended
)
Had problems with the MB, dealership declined coverage, called MBUSA, which called the dealership, and they couldn't work something out after 3 weeks of discussions. Thought I was SOL, then called the dealership again, and we finally worked out something, where the dealership called MBUSA to pretty much split the repair between the 3 parties involved. All documented on mbworld to talk it through, which always helps out by sharing experiences and tips with others.
Only way you can really have a foot to stand on is if you have ever discussed a previous issue with the dealership, and they've recorded it. Now I always go over my car with a fine-tooth comb, and any type of vibration/stumbling/error code/etc, I always bring it up, whether it can be fixed at the moment or not. If the car changes characteristics in any way, something is different or off. The part in question could ultimately fail years down the road, but you had an inclination on the issue way before, which will definitely help in a discussion post-warranty.
Good luck!
If I had to predict the future, if you have brought up any odd idling/engine vibration/cold start stumbling in the past, you'll probably pay 50% of the repair from the dealer if you purchased the car originally from there.