I replied to your post with what I did.
Stock aerial I got OK reception, but it was immediately better once I added the Jass performance stubby aerial (this is just a direct replacement. Takes 15 seconds to change). I have a Sony unit and it said 2/3 bars with stock, immediately went to 3/3 with Jass performance stubby and I got more stations.
Signal has been excellent so far - only dropping out in tunnels.