Wife bought one from aldi's a while ago. Found it annoying because getting in & out of the car, it'd keep moving 'round. I now lives in the back of the car till needed.
Other than that, it is good
Like others have said, I still rather get out, walk around & stretch, but good for when a particular un-named person "just wants to get there"
Our's can be adjusted for either bum, lower back, upper back, upper & lower back...you get the idea
Also has heat (3 settings I think)