I have an issue that you small electronics guys may have a solution for. When I turn off my car stereo, there is a delay for the screen to shut down. Once the stereo turns off there is a loud thud from the subwoofers connected to an amp. I have reduced the remote turn on wire from 12v to 5v via (2) 1k ohm resistors and still does it. My thinking is that there it a voltage spike when the radio turns off causing the problem. What would I use to catch this or how would I "filter" this spike?