DIY dog booster seat for the car. Cut out two bigger holes in the back for the seat belt to go through and tie a leash to the top. Sew a cube shaped pillow for the interior and a slip cover with elastic for the top (for ease of cleaning) and you're set! Straps in your dog for safety and allows them to see it the window, preventing car sickness.
Illustrating "seat belts" for puppies -- Hubpages Top 3 Dog Car Safety Seats and Booster Seat Reviews for Safe Traveling with Your Pet: "Protecting both your dog, as well as yourself and your passengers from potential injury or fatality should not be an exercise governed by price, but rather should be directed by quality and safety features."