I've used it and it work's good. I would use the compound 1st then go to the scratch X 2.0 http://www.autogeek.net/megscratxfin.html
I think you are getting the plastX and the scratchX mixed up
The shipping is high. You have to figure in shipping to get the best deal. This is a good one http://www.discounttiredirect.com/direct/initTireSizes.do