This is something I did when my kids were little, that was when back seats didn't have seat belts and booster seats, were not required, ya, a long time ago. Anyway I made a shelf that fit between the back seat and the back of the front seat. It added about 7" of seat for the kids to move around it. Well the kids are long gone, but we have 2 four legged kids that usually travel with us. One is a BIG Dobe and the other a pretty, well is going to be big Standard Poodle. They get crowded in the back seat and my Dobe doesn't travel well when he is crowded. He kind of goes into panic mode. So this morning I got up and built a shelf again. I carpeted the shelf for more padding and to ensure it didn't wear on the seats. They will love it when we head to the coast next week
Not much, but at least I got to use a few tools today!