I've been using a roadie for 9 years. You need to move the antennae to some place where you'll receive the signal. You should have 3 bars on the upper right corner of the screen. 1 bar and it loses signal. 2 bars is pretty good. 3 bars and you're locked in perfect.
I have to put my antennae in all kinds of different places. I ran an extension antennae wire from the roadie docking setup that's inside the 5er, outside and under the 5er. I have a plug located near the rear of the 5er in an enclosed outside elec box mounted under the rear.
All I have to do is plug the XM antennae wire into that and then place the antennae pod where needed to receive a signal. Usually just throw it up on the roof of the 5er.