Recommendations for driver's seat support?

Can anybody recommend some kind of support/pillow for the driver's seat in a car? It would be very helpful on long trips, I think, more so than going back and forth to work. I need something and I'm not sure what to buy? Any reviews for anything? Or a good place to look?

Thanks!

I have something like this, mine doesn't have the bumps, it's just smooth


I went on a 3 month road trip & was using it from the start, eventually it got annoying so I tossed it over to the passenger side. Even a pillow put down near your lower back will help. I would definitely try different things out.