VW radio removal tool?

You need the vw/mercedes/audio removal tools--I prefer this particular style over the "keychain" style because these have three different ends to accomodate slightly different slot openings, whereas the keychain style only has the one type of end:  http://www.crutchfield.com/cgi-bin/S-ckfNR0xYsLd/ProdView.asp?s=0&c=11&g=754&I=120869001&o=m&a=0&cc=01&avf=N

The xm antenna must have at minimum a clear line of sight to the sky in order to function properly.  Technically it's also supposed to be mounted on a conductive surface like the body of the vehicle but occasionally you can get by without doing that.  Have you thought about the trunk?  Cuz that's probably the only place it'll fit unless he gets a glass mount antenna and mounts it just next to where the rear view mirror is, on the front of the windshield.