Here are some shots of my 2003 Acura TL-S it has two coats of Duragloss so I played with adding two coats of UPP on top of that - came out great (at least I think so) and the UPP layers are slick as snot -
The metallics don't show up so well at dusk but lest you think they are hindered by the combo here's a close up - great clarity and bling bling shine -