Actually you got only about 2 years out of the clearcoat, it seems to me. (unprotected by wax, that is) And I agree, it's too short. You have some mitigating factors in that it's black (finish gets hotter) but it's probably just one of those things. I suppose it's probably too late to say black isn't an optimal color for areas that get a lot of sun. ;-)
Just for grins you might check the used car lots and advertisements for other black '03 Dakotas and see if they have the same problem. My guess is not. I suspect you just got a bad paint job on yours.
I know that the minivan's (at least) did have some paint problems for a few years back in the 90s with certain colors. White seems to have been one of those colors.
As for the headliner, that really is cheap to fix, as others have said. If you often park outside in the hot sun you might take to leaving the windows cracked to keep the interior temp down, that might help.
Your options on the clearcoat are:
1) Do nothing and keep wax on it, religiously. That will keep the color coat intact and keep the body panels from rusting. The clear will probably stop peeling but the whole thing will look like hell 2) use car polish, then wash carefully, then use a rattle-can to respray the clear coat. It will look like hell. But you won't have to bother continuing to keep wax on it. Like #1 this is a "preserve the body panels from rusting" option. 3) wet-sand the areas that are peeling until smooth and all evidence of the peeling is gone. Then scuff them and scuff outside of the areas with a 3M grey scuff pad and scuffing gel (from any auto parts place) and respray the color base coat (several times) then the clearcoat, feathering it into the existing finish. This will look less like hell, and you can also use rattle-cans but the color won't match the existing paint. This is kind of a cross between a decent repaint job and a looks-like-hell-but-preserves-the-body job, and I think it's nutty since it requires a whole lot of effort and the results look crummy. But people do it. 4) Have a body shop do a proper repaint.Since this is an '03, you probably have enough mileage on it that you would take a loss selling it before it starts falling apart, meaning your probably gonna keep it until you have used it up. In other words the economics of it make it pointless to do anything other than #2, unless you have some kind of vanity streak. WIth any luck, sometime in the next 5 years you will be struck by someone in a fender-bender and you can get their insurance to pay for a repaint.
To be perfectly honest, I think clearcoats on most cars are completely stupid. This is one of those "new car buyer attractant" things they do. It's not very utilitarian. I think for most cars it's just a lot better to layer on additional color coats, forget the clear coat, and tell people if they want the car to continue looking good they need to wax it regularly. That's what they did in the olden days and it worked pretty well. Of course it limits the color choices, but shit man, you bought a black vehicle - how many different color variations are needed for black!!!
Ted