Well, I've added one to my E70. I agree that it takes a lot of space but I wouldn't think of removing it --- I get three more bars with my cell phone hooked up to it.

It's easy to remove. Just lift it up in front and unscrew the bolts holding it at the back. I'm not sure about the two cable disconnects though. You might not be able to get to them as they may be underneath your middle compartment. You would need the "cover plate" that would cover the hole left at the back too.