48BIGTRUCKS, go down to wal-mart and get the undercoating spray can stuff. It's about $3.00 a can or so, and it's specifically made for the underside of your vehicle. I just finished doing the entire underside of my truck (which stinks cause it's a LWB :p ) and MAN is it quite! Still quite clean too, only dust, which will wash right off.
I think I'm gonna go get me that duplicolor stuff at wal-mart.
