I'm actually hoping to rent this out rather than sell it, possibly with a laptop.
Do you have a Volkswagen Jetta or Golf with annoying automatic locks? You can disable it with this. You can change quite a bit of functionality, actually. Uses the OBD-2 port.
I don't know much about this -- I've just used mine one time. Unfortunately, the units are kind of spendy, and just getting the software figured out can take a bit of time. Some units only work with a few VINs -- mine is unlimited.
This is a serial port device, so you need something with a serial port to use it. It requires Windows. I have a laptop that works with it.
My device seems to work with most Volkswagens 2004 and older. There's all kinds of models though, that support newer vehicles. I don't think it would work with anything older than OBD-2 without an adapter.
No particular pricing in mind yet. I figure I can try to do it with you, or I can let you use it all on your own time with a deposit that covers what I paid for the setup.