If you want to keep your vehicle interior smelling sweet, it pays to pet proof your upholstery. Pets can be a comfort, but not when they have bladder control issues or when their untrimmed claws accidentally poke holes in your leather seats.
Pet car seats help protect your vehicle from pet passengers by putting a waterproof layer between your pet and the seat. Many covers offer thick, comfortable padding, and some have thermal layers that keep your pet warm by reflecting his body heat back at him. They're available as pads, cushions, hammocks, blankets and the standard covers you might see on a living room couch or chair.
In the case of hammock seat covers, the ends of the covers are secured to the front seat head- rest or side straps, creating a big U-shaped enclosure and making it much harder for your pet to slide off the seat onto the car floor. This particular style is also good at containing messes and pet hair.
Pet car seat cover manufacturers haven't ignored aesthetics when developing their product lines, either. Covers are available in many colors and patterns; some also have optional monograming. They'll typically be made from washable materials so you can just throw them in with your other laundry, but check the care instructions just to be sure.
Microfiber is a popular material for upholstery covers. It's strong, looks plush, and pet hair comes up easily either by vacuuming or wiping with a damp cloth. It can get hot, though. If you want your pet to stay cool during summer excursions, stick with a natural fiber like cotton.
Most pet seat covers work well at protecting car upholstery and making pets comfortable. They aren't designed to keep pets safe, though. For that you'll have to go with a pet restraint product like a pet safety car seat or harness.