Let me start by saying this cushion transformed my road trips. As someone who commutes 2+ hours daily, the difference is night and day. The memory foam molds perfectly to your body without that annoying 'sinking' feeling cheaper cushions have.
The non-slip base is LEGIT - no more doing the awkward butt shuffle at stoplights to readjust. Even during sharp turns in my Jeep, it stays put. Bonus points for the included extra cover (machine washable!) which saved me when I spilled coffee during a morning rush.
Here's the real test: Last month's 6-hour drive to Vegas? Zero back pain. Normally I'd be popping Advil like candy. The ergonomic design actually improves posture - I caught myself sitting straighter without even trying.
Two minor cons: 1) It adds about 1.5" height - fine for me at 5'7", but taller friends might need seat adjustment. 2) The black cover shows pet hair easily (I keep a lint roller in the glovebox now).
Pro tip: Don't limit it to your car! I stole it for my home office chair during Zoom marathons and my WFH setup will never be the same.
Final verdict? Worth every penny if you spend serious time behind the wheel. My only regret is not buying two so my passenger stops stealing mine!