I'd say, if the cover looks all chalky and dull it's gel-coat.
Either way, 'regular' auto products CAN be used. If indeed it is gel-coated (and you are positive it is), jumping up to products for boat, RV etc. can really make things pop.
It seems to look like paint and is glossy, but I don't know if gelcoat is hard to tell from a regular paint or looks distinctly different. I don't think it's chalky, but it's white so maybe it's just hard to see.
Dont think you will find a cover for a truck that is gelcoat all around man. Im positive there is either paint with clear or baked on paint that is extremely hard. There is a major difference between gel and clear coated paint. Either way, start with a heavy cut compound - if the is no white residue on the pad (or powder flying everywhere when slapping the pad), then that tells you it is painted. If the is no white paint transerring to the pad, then that tells you that it is coated.