I know from personal experience that Thorn only uses dye for his figures. For his vehicles, he uses many, many coats of spraypaint (if you look at Thorn's page and look up NF Custom HISS, you'll see what he did for me.

). It has a seemless look to it... tre spiffy.
I've also seen somone else do a dye job on one of the Ninja Lightning Cycles... here's the link to the topic, and there's a link to the guy's pics as well:
http://www.joesightings.com/ubbcgi/...c;f=19;t=000594