The epoxy will streak but it's not from the rain.One problem is in an uneven overlap while spraying,so the thinner spots wear faster.The big thing is the air pattern that flows over the car like watching the wind tunnel testing,there's debris in the air so wherever the most airflow is contacting the surface is where it wears the most.My old mustang was left in black DP and the roof went to hell in a pattern on each side of the roof.If you want the old school look don't play with flatners and forget the DBC500(it'll go to hell from the weather real fast-I won't even use it on jambs for the final finish even though PPG says you can).Use their Flexed-n-flat clear,I think its # is 2060 but not sure,the name is correct though.I've been wanting to do an old school scooter in it but haven't had the chance.You can mix it with topcoat clear to pull it up to an eggshell and semigloss which is a bit more durable than straight out of the can.Using flattner in topcoat clear or singlestage usually makes them chalk out alot faster.Just remember if you get any dirt in it there's no buffing it out,what you see after it dries is what you get.
