radio antenna sensitivity?

[BMW DIY Guy]

Morning all!

I searched the forums and didn't come up with anything so my apologies if I missed a thread on this already.

We recently picked up an E53, and the stock stereo was in place for about 3 days before I installed an Avin Avant-2 deck. (diy pending!) ((yes a DSP car, that was an unpleasant surprise but I worked around it))

We didn't run with the stock stereo long enough to really get a sense of how well simple radio reception worked, so I cant say if what I am seeing is default behavior or because of the swap with the Avin.

Radio reception is really inconsistent.. we are outside seattle, good local radio FM and AM reception, but the quality of the reception really comes and goes while on a simple 10min drive. It is noticeably worse than in our other car (E46 M3 also with an Avin Avant-2 and stubby sport antenna).

Is this default E53 behavior? Aspect of changing out the deck maybe? Where *IS* the antenna in an E53? Any suggestions or troubleshooting?

Thanks!