body sealant??? stuff for truck and floor pans

I use polyurethane caulk made by loctite at lowes.

Clean, scrape, clean with judicious amounts of alcohol, the apply.

http://www.lowes.com/5-10/_/N-2z8vj/pl?Ntt=polyurethane+caulk&rpp=16

basically 0 shrinkage, high grade solids, acts as an adhesive too, remains slightly flexible forever, not made out of latex, not water based, bad ***, sure to be outlawed in CA due to it working great and not being comprised of recycled papier mache'.

Thus far, i have used it for sealing and bonding an expanding gap in wood and seam sealing my entire Duster after sand blasting.
It is a little more expensive than regular shi%%y practically worthless latex caulk.
Normal caulk sized tubes are about 6.50 where I live.
.