Sure, it's relatively easy, depending upon the hardware you have. The simplest method would be to use a standalone CD recorder and connect it to your tuner or receiver. Most car decks I've seen will play back MP3 or WMA files, which would easily allow you to cram several hours of music on one disc at acceptable quality for car use.
It seems to me that most people would opt to rip & burn from their own CD collections for such a project. Why do you want to use radio? I can see the appeal if you have access to stations that play a wider variety of music than you yourself own, but it seems to me that physically hitting the FF button to skip commercials would be very cumbersome. You can edit them out as you record them, but that's not a very elegant solution, either. My preference would probably be too simply rip tracks from my CDs or hard drive to MP3 and burn them with NERO...