I am a firm believer in pet car seats. When my toy poodle was only about 9 weeks old (about 15 years ago), I had a wreck in my car - totalling the car but not injuring either of us - because he was running around in the car. Of course, partly my fault too for fussing at him and trying to get him to sit on his side. Sure, right - like he was going to listen!
Anyway, I was quite nervous about him riding in my car from then on and so when we got Tatum I had to search around for car seats. I got the lookout seat which looks like this...
http://www.pettails.com/consolelookout.html ... sorry, can't seem to post the picture here. Tatum absolutely loves it. She jumps in it as soon as I put her in the Tahoe. I think she feels safe and happy that she can see out.
No matter what kind of car seat you use, I really think it's an important thing to have.