I should have looked for one of those cup brushes JonL, although I did spend a few weeks prepping - grinding, welding holes, sanding/scuffing where the paint was intact, scrubbing with cleaner. I figure about 20 hours of prep and 2 hours of applying the liner.
It was very easy to apply. My only screw up was I didn't wear gloves and got some on my hands. This stuff sticks really good.