Yep, I'm a LINE-X dealer as reported in other sections of this website.
Ask the dealer what he is putting on the liner. It's either Ultra Shield, which is a UV topcoat, or even perhaps DuPont paint (or a generic). If you take care of your liner, you really don't need that stuff. Put either Just Once (
www.justonce.com) or 303 Aerospace on the liner 4 or 5 times a year and it will always look as good as new. Don't use any silicone based product, it makes it too slippery. If your not disciplined enough to do that, then consider a topcoat.
I read about 40 truck related forums every day. 90% of those who use Herculiner or Duplicolor are sorry they used it. Most of them complain that it chips off in a year or two and it looks bad after a while. Unless you have a way to spray it on, you have to put it on with a brush, and it looks like you put in on with a brush. For the other 10% of the users AND myself, it's perfect for farm equipment, trailers, beater trucks, or the like, but I can't imagine using it on a $25,000 to $40,000 vehicle. The quality and chemical make up does not come close to LINE-X. I'm telling you, "You get what you pay for." applies here.
Black is the most popular color. LINE-X has "standard" colors like red, navy blue, etc. Or, the LINE-X dealer will actually color match the trucks paint using the factory paint code. The most popular color we spray is Ford's Arizona Beige. It's drop-dead beautiful. Keep in mind that darker colors work better than light colors. Light colors look dirty if you don't keep them really clean.