- The dog seat cover offers both PU and plush features. Flip to the PU side for a waterproof, stain-proof, odor-proof and fur proof surface. Flip to the plush side for soft, cozy comfort just like a home bed ensuring your pet feels warm and cared for on every road trip. Plus, it easily converts from a dog car hammock to a dog bench back seat cover or suv mattress/trunk cargo liner. % & - This Back Seat Extender for Dogs offers 40% more space and 2x extra padding for comfort, supporting up to 400 pounds. During sudden braking, it prevents your dog from falling into the footwell, keeping your dog cozy and secure during travel while protecting your back seat and car doors.