I listen to audio books in my car also, but my 90min daily commute is nothing compared to truck driving! Still it is really fun to listen to books.
I also totally agree with you about unabridged books being better. I recently bought a batch of second hand audiobooks on cassette. There were both abridged and unabridged books by the same authors. Now that I've listened to both, I'd say that with the abridged books, I always just wanted to get through them to find out what happens. But with the unabridged books, it felt like the journey though the book was fun in itself, and I enjoyed the experience instead of having that attitude of conquer and finish.
The other option people may not have thought of (including me until recently) is the most obvious one... the public library. At least in the US, I think most libraries probably have a nice collection of both cassette and CD audiobooks. I've just discovered this at my tiny local neighborhood library, and will next try some of the larger branches for a better selection.
This seems to be the best way to go for me, and is free! Of course, with one of the online rental or purchase services, you probably get much better selection, and you never have to leave the house. It all comes down to individual preferences I guess.