ContourSit Car Cushion by Relax The Back®
Product Review (submitted on August 4, 2011):
I bought it for my commute and then took a trip from TX to RI. No back pain on the trip...let my MIL try it too. She has had a lot of pain for years and loved the cushion. I left it with her and will be getting another ASAP. I tried more expensive ones without the same good results in the car (Honda Civic '10).