Okay good to know that the problem could still be in the keys themselves after all. Can't rule out the wiring and amplifier though. As a matter of fact, where is the amplifier located exactly and is there some way to test it? Wiring is in the hinges right? It's just that everything else, the rear lights etc. works fine but I guess it would be possible that it was just the remote control that wouldn't work.
And altogether, the key B now usually works like 75 % of the time while initially the key A was like around 5 % certainty.
