So I just bought a car with a Pioneer AVIC-D3 in it. I noticed that the reception is really crappy, and everytime I go under an overpass, my radio cuts out. I suspect that the antenna is either internal to the head unit or the head unit is not attached to the stock antenna.

 

I'm thinking of getting the antenna on my car shaved.

 

Can anyone let me know if there is an internal antenna inside the Avic-D3 or if it's connected to the stock radio antenna? I know there is an antenna for the GPS, but does that antenna also get radio signals?

no internal antenna on any radio, if you get any stations then your antenna is probably connected, a lot of new cars have short stubby antenna's that have a signal amp, if the turn on wire was not hooked up to the signal amp then that could explain your problem.

 

it also is very helpful to know exactly what king of car you are dealing with.