It's possible, but you might not be super enthusiastic about the extra steps it takes.
1. Jailbreak the iPod.
2. Install VNSea (a VNC client)
3. Install a VNC server on your computer.
4. Install a wireless router in your car.
5. Configure VNSea on the iPod Touch to have an entry that corresponds to the IP address of your carputer on the wireless network.