RIGBENDER- I did one of my cars two-tone, some may disagree, but my opinion is as long as the two colors are seperated by trim of some kind, I'd do both at the same time. Would suggest painting the top color first though, if you drip any on the lower section while bringing your roller up (and it's likely you will), it's easier to wipe off with mineral spirits as opposed to dripping on the freshly painted lower.

QUESTION FOR ALL- Searched thread for but could not find definitive answer: What causes severe roller marks? Having trouble with horizontal surfaces (roof, hood, trunk) while verticals have no marks. Opening hood and trunk helped some, but still there. Thanks for any help.