Radio reception question

LOL. You can think of it that way if you want, but the REASON it was there is to help reduce radio noise and THEREFORE help reception. The two go together hand in hand.

A low noise floor at the antenna terminals of ANY receiver equates to better reception, better signal to noise ratio. It doesn't matter if you turn the engine off or shield the thing, "less noise" at the radio means you are going to be able to RECEIVE weaker stations than you did when the higher noise was present.

This is exactly why receivers are measured in terms of signal to noise -- because the noise makes a difference.