Yeh lots of red flags with that. The connection should work anywhere on the bus if the protocol is handled properly which I don't think it is by the sounds of it. Putting it in the back probably adds some delay that by chance/luck band-aids some data conflict/collision and allows it to work better. Definitely would be a good thing for to hear about some other peoples experience with this.

__________________
1988 325is (purchased new) sold
2004 X5 3.0 2005 X3 2.5
2008 X5 3.0 (new to me)