My back and neck are always in need of adjustments and massage due to my terrible posture and excessive electronics use. Normally, I keep a few lacrosse balls in the car and roll on them as I drive- it’s fantastic. I know this would look tacky, but I’d love to just get a massage seat for my M3. There are a bunch of third party ones on Amazon for regular cars. However, they are only DC or AC options and as far as I know there’s no USB ones available. Anyone know of options for that?