I use a foam dog car seat in both the car and RV, and it works great for two small 10lb dogs; because I donít have any human passengers. I also have a back seat cover for one car that is fantastic for that car, as the the monsters have taken over the back seat permanently. One thing that seat cover came with was these tethers that go into the seat buckle. You can get them separately, and I thought they would be perfect for the RV couch.
Vastar 2 Packs Adjustable Pet Dog Cat Car Seat Belt Safety Leads Vehicle Seatbelt Harness, Made from Nylon Fabric https://www.amazon.com/dp/B014W40TSW..._69LdDbQGEGCZQ
Mpow Dog Car Seat Covers with Mesh Visual Window, More Durable Scratchproof Dog Seat Cover for Back Seat with 2 Dog Seat Belts & Storage Pockets, Non-Slip Washable Dog Car Hammock for Different Cars https://www.amazon.com/dp/B07J5XJ8J1..._TcMdDb7KXZ3KK
Pet Gear Lookout Booster Car Seat, Removable Comfort Pillow, Safety Tether Included, Installs in Seconds, No Tools Required, 2 Sizes, 3 Colors https://www.amazon.com/dp/B0015MLI30..._VeMdDbFXVKS70