Originally Posted by edwinm3
If BMW NA wants to know if your car had a tune they will know and use that excuse to deny any warranty claims. Of course that will be for major repair bills.
Bingo. Here's the deal: changing ANYTHING on your car that's not part of the BMW maintenance program *can* kill your warranty. It really doesn't matter what your dealer says.
The question is, when does it become a problem?
Some dealers will make it a problem on the next service, some won't. Your real concern is the risk of something BIG happening and having your claim denied because you did something that's outside of the maintenance program.
This is why tunes, check-r, and messing with cats are no-nos for the risk averse like me. The odds are *probably* small and if you can afford $35000 if that risk triggers then go for it.
If you want to stay in the safe zone stick to cosmetics and an axel-back.
Remember, none of the vendors or fan boys who tell you go for it will be sending you checks or lawyers if your engine blows due to a manufacturing defect.