I have back issue which has made my C400 w/sport suspension painful to drive. I have been looking for an ideal lumbar suppport pillow and finally found the perfect solution. The Temperpedic travel size lumbar cushion fits the seat perfectly. Most are bulky pushing me way out of the seat, but this one is absolutely perfect for me. Funny thing is that it sucks with my Honda Passport. I guess its just the perfect dimensions for the C series seats.

https://www.tempurpedic.com/other-pr...-travel/v/791/

Available for $40.14 on Amazon.com