Originally Posted by Zuzu
Sure is mate..
Back in the day, I had my 135i vert in for ECU upgrade and left the JB in..
Just because yours didn't get noticed doesn't mean none of them will...
Way I see it: It's a decision each individual has to make for themselves - balancing the time/effort of removing/reinstalling vs possible consequences of it being found on the car.
At the end of the day, make your own decision but I just can't see how it's a good idea to recommend that someone take a warranty-voiding risk like that for no reason other than to save 30 minutes of effort - regardless of what you/I may or may not do...
It's like what Clarkson says about Alfas: He'd buy one himself but he'd never recommend one to a friend.