Originally Posted by iBeJayKaying
If you want to get into technicality, then yes, it does void your warranty for headlights. The point is whether the dealership knowsor cares if you modified something or not. Most (not all) dealers (here in SoCal as an example) won't make a big deal about it until there is a component failure, and you come back wanting free repairs done due to failures caused by a non-BMW approved part.
If you have a failure caused by AiB or Alpine, you have a much higher chance of getting away with it using warranty than if you have component failure caused by OSS. If your OSS fails, and it's damage outside of what OSS covers, you're pretty screwed. And if something happens and you had GP Thunders....well....I doubt that would ever happen, since they are a simple bulb replacement.
Benefit of GP Thunder, AiB or Alpine kit would be reversibility (and with it, improved though still likely imperfect ability to hide the fact that anything was ever modified).
I am interested in a set of AiB, if I install them, do I lose warranty? and what do you mean by reversibility if I install a set of AiB?