Check the internet for other prices, this is just the first site I pulled up:
Snoozer Lookout Booster Dog Car Seats, Pet Car Seat in All Sizes and Colors
Depending on the size of your dogs, you can go either the medium or the large. They have a little built-in drawer for stowing leashes, harnesses, water bowls, food, snacks, etc. They're high enough that the dogs can look out the window. And they're secured by the car's seat belt, and then a "hook" device that fits over the seat belt and snaps onto the dog's harness so they don't go a'flyin'.
I have a gray "pleather" one to match my car's interior.