Originally Posted by iBeJayKaying
From your other thread. You can just hit edit if you want to amend a comment, rather than creating a whole new thread.
IMHO, it highly depends on how anal your dealership is. My friend has had a dealership try to void his warranty just because he had aftermarket wheels on his car. Course, that didn't hold up, but you know what I mean.
I've rolled in to my dealership of choice with aftermarket wheels, muffler, coilovers, and filter, and haven't had a problem.
Just use common sense, to a certain extent. For example, it's highly unlikely that a dealership will void your warranty based off of your getting aftermarket wheels, or aftermarket mufflers. Generically, these things are viewed as "cosmetic" modifications, that don't impact the performance of the vehicle (at a dealership, I mean).
Now, if you changed out the X-pipe as well, and not just the muffler, AND if something related to emissions went wrong with your car, then you'd be pretty SOL.
Pretty much, stick purely cosmetic if you want to be 100% safe. An alternative would be to purchase Dinan parts: contrary to popular belief, BMW does not warranty their parts. However, Dinan's warranty matches your factory new car warranty.
Dealerships don't just jump up and void your whole car's warranty the moment you put a part on. It's only when something goes wrong that they won't claim responsibility for the components affected.
For about 10k, I think you'd get away with a few things, depending on what you purchase (I.E. Don't buy an Akrapolvic exhaust thinking you'll have 8k left over for mods): Wheels, suspension, exhaust, cosmetics (grilles and such), performance air filter (and scoops if you believe in those toys).
I've had the same experience with two local dealers here. For the most part, they complement me on the modifications and only once asked about the software tune when they were reflashing the car to make sure they could do it without damaging the car. It is highly dependent on the dealer so I would do your research and see where others are having success.