Thanks to Polaris for coming up with the AutoTop Arduino modification, I spent the day doing just that.
Got everything ready. Resistors, transistors, wires, arduino board, etc.
Complete. Looks a mess, but essentially it's something you plug into the switch harness, and the switch plugs into this, so it sits in the middle.
Wired up
And a video showing it working!
https://youtu.be/9JIRxSIefpA
Over the moon with it. This, coupled with the modification to allow me to do this on the move without the handbrake is brilliant. Approaching a roundabout in traffic? No problem - don't have to hold the button, stopping the roof to change gear and continuing the roof. Just one click and I'm done. Also when setting off in the morning, I can just buckle up, click, and start driving
The whole thing cost about £30 including the board and required parts.