I have a lookout II.
Addy loves it, she can lay down and strech all the way out without touching the sides! It is big enough for her plus 2 more small pups.
The seat comes with 2 seatbelt attachments, I found them to be a little heavy so we just use her Dogo harness and a small lead rigged around the belt.
The carseat stays in place really well and has a little pull out tray for treats, extra clothes and leashes ect...
The lookout II is very big! I drive a 4runner and it takes up half of the backseat!
It was a little expensive, but worth every penny, Addy stays in her seat and is safe in case of an accident.
I purchased mine on ebay, but I had to wait a while for exactly what I wanted. GW little has an awesome selection of carseats @
www.gwlittle.com
prices vary depending on what you are looking for. I paid $65 for mine and I am very pleased.
Hope this helps