I found a cool way to simulate that semi-gloss look vinyl roofs have. If I put on regular semi-gloss paint it will most likely cover up all the detail and it won't look like vinyl anymore! What I did was ( by the way I used this technique on the AMT/Ertle Ford Woody) sprayed the roof with flat black to maintain the vilyl detail. Then I took a Rotary tool (Dremel tool) whith a buffing wheel then next, I set the rotary tool to its lowest speed and carefuly polished the roof until all the gloss was uniform. But remember not to press on the tool too much, the friction will distort the surface. Just aply light pressure and always keep the wheel moving. Thats it you should have a good if not great looking roof. I hope this helped you like it did me! Good Luck!!