[Walt Fricke]

Your dash has a cut-out (covered by the vinyl) in the dash for the headlight washer function - assuming you don't have that on your car. It is a momentary NO switch, just what you need to wire into a cannibalized door opener you mount behind your dash, reachable by removing the instruments, some or all. That would allow relatively easy access to the opener for battery replacement, assuming you didn't fabricate the circuit needed to provide 1.5V or whatever the opener uses from your 12V system and skip the battery.