Review on RELAX SUPPORT RS5 Lumbar Roll Cushion: Adjustable Car Seat Lower Back Support Pillow for Pain-Free Driving Posture - Customizable Firmness Levels by Leah Johnson

-- I found that one (of three) memory foam pads in the case was all I wanted for my lower back. As mentioned in another review, after 8 hours in the car (mostly indoors) the pad was flat as a pancake! It took THREE FULL DAYS of sitting to regain its original thickness. I think regular low to medium density foam will work much better and be stable. Memory foam (especially cheap stuff) is NOT for everything lol. Another issue that has been mentioned elsewhere is the lack of a zipper on the case. Actually, the reason for this is obvious. Since the bar is in the rear center of the body, it may damage / leave marks on the seat cushion. To me that makes sense!