I have used the vinyl paint in the past and if I remember
correctly it worked out well on two cars I did. This was of coarse a while back. I did a black roof on a Nova and a brown roof on a Cutlass. The black came out better. Not sure what brands of paint it was but I got it at a body shop and paint store. It was a specific vinyl paint that was applied with a sponge. Sorry, my memory isn't better but I hope it helps. By the way, if your just trying to make it look "better", I used to use oldschool black shoe polish on black roofs. I would apply it several times, work it in good with a plastic type scrub brush, to get in all the crevices, and then wipe off and buff. It really came out well. I used to have all kinds of people coming to me to do their vinyl roofs back in the day. The old style black shoe polishes have a weak dye in them that set into the vinyl to cover up the bad spots. And it really beaded up well, too.