well, the switch... external... if you can mount a clear window on the inside of the handle, then you should be able to mount a LED/camera from a mouse that can be made waterproof to the extent of what you are doing... that would be a pretty reliable switch... just need a circuit to let whatever controller know the circuit is open or closed, (possibly by transistor?) as for the steering wheel locking. I have not seen the parts themselves, but the general method for that is a pin directed into the column... that as I have seen on other posts other people have found to be a problem, and have either shaved, or removed it... now when I said "Keep as much of the original system as possible" the locking pin would be in my opinion "Expendable" and the system should bypass when necessary the factory remote coding, but allow the factory key and remote to work... BTW... I set up a computer last night to use the bluetooth proximity detector as I mentioned earlier... and so far so good... I can tell it how far away I want to be able to get before it locks up, and how close I want to be in order for it to unlock etc... I also know there are kits etc for micro computers etc that could be used for controllers... the other option there though would be an old laptop with a damaged screen, that could be cannibalized for a controller... would just need to get an appropriate dc-dc convertor... if the computer is new enough to boot from USB, then the OS could be run from a key drive this would save a good bit of power, but the drive may need to be replaced once in a while, but taking that would disable the system (leaving for the weekend, leaving at a shop etc...