Controlling power windows, mirrors, heater, etc in a car with a tablet pc

I would like to add power windows and mirrors to my van. I can buy them used from a wrecking yard but then would have to tear up part of the interior to install them. I was wondering how difficult/expensive it would be to connect a tablet pc to the device via bluetooth - or some other wireless option.

I've been messing with the HC06 bluetooth module and my Android phone using App Inventor 2... Works a treat... If you connect the HC06 up to an Arduino there are examples on the net for controlling motors..