Just received my clay bar and lube from Chemical Guys. The bar is listed as 4 oz (113g). They say you can do about 10 cars with it (although they give you enough spray for 4 cars). I read somewhere that it`s good to cut the clay bar in a few sections so that you use each section per car. Also, using smaller portions is safer since, in case you drop it, you won`t ruin the whole bar. So just curious as to if I should cut it into 2 or 3 sections. Any other tips/suggestions for a newbie to claying?