Hi Bicky, my back was perfectly fine until I drove the Prius for a few hours and then my back started hurting. I wasn't doing anything else. My wife and I have gone over this again and again trying to make sure it's the seat and not something else. The interior guy said the seat was uncomfortable with his bad back as well. I have an orthopedic back support and seat on order from Obus Forme. My wife drove last night so a total of 3 hours of driving and I was ok. My arm hurts too much to drive but as a passenger I'm ok. I would love to keep my Prius but with the exception of this back support I've tried everything except a package IV or V. My dealer doesn't have any of those coming in anyway. A power lumbar versus a lumbar support cushion should be about the same. For certain I have sciatica regardless as it's chronic but this is something different. i don't know how the seat is pinching a nerve, but it is. I can sit in the seat and I will begin to ache all over again.