Correct.
GQ was correct and on the money. 25KHz Vs 12.5KHz channel spacings, deviations halved result in exactly what he said. Now somebody transmitting on Channels 79 or 80 nearby the troubled radio that could be an old 40 (Full DIN size is likely an 80ch radio) would see possible issues, not likely here.
Incorrect, noise can come from anything such as bad radio front-end, bad antenna, loose fittings, corrosion on the fittings, hot-dry air blowing over antenna, poorly mounted antenna and location, etc. etc. Common issues seen now are bad/noisy electrical devices in the vehicle like cheap phone or USB chargers, cheap mains inverters or even in some cases, failed alternator diode. An AM guy who has been playing with radios since the 70's should know this....![]()