I coated my Lower cowl, exposed frame, chrome exhaust covers, and instrument panel with bed liner about 12K miles ago. Looks great, washes easy, and is easy to fix. Another forum had a caution about which brand to use - I think it was Dupli Color but won't promise. Fixed my ugly lower cowl - I just polish the timing cover with compound once in a while. Looks like chrome.
YMMV

Shiv