The only thing I use the ball for is some wheels. I have seen it used on paint, but would not recommend it. You place it into your drill and work away. I wouldn't use it on paint for a few reasons, and the main one being that you cannot normally control rpm's on a drill which could cause damage to the paint. The second one is that it would take forever to do a vehicle. I would invest in a Porter Cable or
Flex with the
Lake Country pads and a good polish,(for whatever you are trying to accomplish) etc. for the weekend warrior, and go from there.
As far as the power ball on wheels, I do like it (especially for my Pro Comp Alloys, which have circlular holes around the peremiter of the wheel)...the ball makes waxing and polishing in those holes a breeze.
I am sure others will also offer some input on this subject.