Hacking your car.

Has anyone tried or know anything about this?

I'm not referring to putting on more LED's in the interior than already needed or bigger spoilers. I'm more interested in the little computers inside it. The SatNav systems and media players.

I've always owned 90's era cars, my last car was a 92 Honda Prelude (and I was completely and unashamedly juvenile about it, fat exhaust, big rims etc...) but I just recently upgraded to a 2013 model BRAND NEW car. It's a huge transition for me, having always been in older cars. Proximity keys (mind blowing), touch screen, blutooth streaming, automatic lights rear parking camera's, voice control, massive 7 inch touchscreen. Hell, it's even got sensors to tell me when my tires need air. I've never had so much tech available to me in a car in my life before. I'm only 23, so more older (or richer) folks who've had a few cars already are probably, "been around for ages son. My BMW had that when I was just 20".

But after playing around with it, I was wondering if I could do more to hack the on board computer or media player on board. I dunno what to do what exactly. And I'd definitely be voiding my warranty... But hell. Almost every electronic device I own is hacked in some way. I'd like to ad my car to the list. Obviously this is very sensitive work, as cars become more reliant on technology to problem solve and even fix the cars. They just plug in a few cables and they can run a diagnostic. So I'm aware there may be huge risks involved. But I'm more curious than insane.

So far, the only thing I've managed is more of an iPhone tweak, and I've managed to bypass the "handbrake has to be on to watch any media content" block, thingy. So now I have google maps on my screen.

But, surely there's more here? I just want to know if anyone know's a forum I can access or knowledge base?

Much thanks!