I was down at the local canadian tire today and they have simoniz power polishers on sale for $70. These are electric, 2600rpm units. Are these any good? My '01 black chevy has alot of real fine scratches that I'd like to get out. To have it done at a shop it was going to cost $100. I don't know how/what they use like if its way higher rpm or what? $70 seems kind of too good to be true. Input?