We have two dachshunds and the larger boy who weighs about 19 lbs uses this. He needed a wider one for his long body. https://www.amazon.com/Snoozer-Lookout-Seat-Small-Black/dp/B000634MXM/ref=sr_1_47?crid=1WK3CCO9R84LS&dchild=1&keywords=dog%2Bcar%2Bseat&qid=1631039163&sprefix=Dog%2Bca%2Caps%2C258&sr=8-47&th=1

Our smaller girl, she is about 10 lbs uses this. https://www.amazon.com/dp/B004ZJOKIU/ref=dp_iou_view_product?ie=UTF8&psc=1

I’m happy with both beds and have been using them for the last 5 years or so. They are securely attached to the back seat and have seatbelts for dogs. We have a heated blanket for car as well.