We have a PPG clear (it has a very slight amount of milky-ness to it) primer surfacer at work. It's sold only in a spray can, is UV cured, and is fully dry in 2 min. The only problem is you need the UV curing lamp or it won't dry at all (they cost about $1500). Your also limited to primimg only small spots, about 9"x9". It actually works very good, but has its limitations.
Austin