I've checked that item out myself, Sarah. Dh built something like that for his SUV, with wooden boxes covered by foam and then large fluffy comforters. But the inflatable thingie looks like it would fit tighter (and be safer in case of an accident).

With my last two seniors, I also used seat belt harnesses, and we cross-braced them so that the dog sitting in the passenger side seat (facing center) had her seat belt (from the passenger side) buckled into the driver side receiver. Then we pulled it so it didn't have a lot of play. This helped keep the dog snug against the seat as well. We buckled both girls in this way, facing each other. It was cozy, but their hips and and lower halves were snug against the seat. We could drive mountain roads, stop short, etc, and the dogs would barely move.

Both had orthopedic issues, and it was important to us that they have a smooth, secure, safe ride.

My current kids ride in crates, and even with a good fitting crate and layers of blankets to absorb the impact, I'm still surprised how much they get jostled around. But seniors especially need more than simply a place to stretch out a bit. So thanks for the recommendation. I definitely think I'm going to get the inflatable platform sooner rather than later.

Cool! Mine just goes in the back of the van - seats UP.