let me start of with saying i'm a total newbie!
I recently bought the car of my dad (he bought himself a new Opel Vectra)
and I was thinking about implementing a pc-system in my car
that not only reads the parameters of the car
but controls lights, heat, windows, doors through a simple
interface on a touch-screen.

My question: Is this possible and does such a thing already exist?

Where can I find more info? I've read to the forum here already,
but I've only find about reading and showing parameters from your car,
but not actually controlling for example your head-lights or door-locks or

any information would be grately appreciated