On my orginial Zephyr they hung condensors on everything, even the oil pressure sender. I think trucknix is correct as RF coming from the ignition is the biggest problem but also such things are fans can be 'noisy'.
You live on flat ground in a very populated (in general) place. Propagation of the AM band is as good as it gets on flat ground as the low frequency of AM tends to follow the curvature of the earth. Problem is, there isn't much programming worth listening to now days. Everyone has gone "Bluetooth" and such.
