Thanks for the comments!

xintersecty: It may be less expensive than you think, but the cost varies depending on what you want to add to the PC.
A basic system will cost you about 500$ more or less. But that's just the case, PSU, motherboard, touchscreen and HDD.

05Aveo: This setup is not specific to my car, The only two things you need to look if you can do it is: Can you find a double DIN trim kit from metra of scoche for your car and do you have room to place the the pc case somewhere. I initially wanted to place mine under the driving seat since there a nice carving down there but The OnStar unit is allready there and can't be removed cause the car refuse to start without it plugged.

Since you guys seems to like this setup I will make an How-to for this Setup. I myself ran into some issue and my experience can help you guys save time and money on it.