Originally Posted by shashankmittal

1. BMW recommends not to connect BMW unapproved aftermarket electronic devices to your car, as they may interfere with the car's electronics, since everything is computer controlled.
2. Being said that, in case you have any electronics related problem, I would recommend you remove any of these connections before taking your car to the dealer for service.
3. Regarding other mods, yes they do void the warranty...in some cases the warranty gets voided only for the replaced parts, but in some cases it may also result in much more than that...e.g you install aftermarket brake pads, BMW will void the brake warranty
4. Insurance companies tend to charge more for cars that have been modded.