Snoozer seats are great and you can get different sizes that would fit multiple dogs. They are so comfy and solid and are kept in place by the car seat belt. They have a tether for safety, I think I got it as an extra?? My 10 LB dog can easily see out, but you can always put a pillow etc under the Snoozer seat to raise it up more. Can get good prices if you look around the web.
Good hunting