Halfords truck bed liner which is about £10 a can.
It does give very nice finish and as the name suggests is for the beds of pickup trucks so its quite tough and scratch resistant. I',m doing all the roadside sides of my wheel arch liners in it as well as the new lower panel.
On the down side it does clog the spray can a lot so make sure you spray in one long spray if you can and after spraying take the cap off and submerge in thinners.
These are my wheel arch liners I did at the same time
Pic of the stuff...