Dude, any decent stereo shop can do it, and I'm sure LTBMW could do it too. It shouldn't take more than an hour at most to do it properly with a fuse tap.
Most people mount it high up on the windshield or on the visor. Some even put the detector in a tissue box to hide it on the visor.
Let me get this straight... You are swapping out parts designed by some of the top engineers in the world because some guys sponsored by a company told you it's "better??" But when you ask the same guy about tracking, "oh no, I have a kid now" or "I just detailed my car." or "i just got new tires."