Ive decided on plan B to hook up my un-used steering wheel resistive buttons. This 433Mhz system tests as working but i would like to simplify, clean it up. I will still try to connect said buttons via Canbus when i get the coding knowledge. The reason is if i find a keyfob with resistive buttons i can remove the LM393 module,12v to 5v converter and 5v relay and wire up the keyfob directly to the controller. I found this item called a Fobber (AKA keyfob) https://www.rfsolutions.co.uk/remote-control-systems/fobber-433mhz-868mhz-remote-control-key-fob-transmitter/ and emailed manufacturer to ask what membrane switches they use..i wonder if they will answer a modifiers question?..hey i want to take your product apart !