I work for the dealership and took my chip out before getting warranty work - everytime. And no - I didn't tell anybody about it.
With that being said, I can't blame BMW. Why should they warranty a car that isn't performing to the specs it was designed to perform too?
That's like buying a new computer - opening it up and changing things around - and then expecting the company to warranty something that you very well might have caused by messing around.
Just don't get caught and your fine - if you get caught, then BMW shouldn't be expected to foot the bill.
Chipping my car - I know full well that if they catch it I'm screwed. and I'm accepting that.