Why does the AM radio on my 2008 Chevy Malibu not work sometimes?

[amanners]

The AM radio in my '08 Chevy Malibu will occasionally completely drop the AM radio station to which I am listening. I understand that AM sometimes suffers from signal loss, but this is not the case. The loss of sound is usually preceded by me hitting a bump in the road, and I find that once I restart the car, the signal is immediately back. Anyone have any suggestions?

 

[Silverado]

take it to the dealer and have a specialist look at it sounds like a wires issue, the antennas aren't good friends with automatic car washes either..