In the old days, having dozens of quart cans of paint on the shelf was normal for several reasons. But paint has gotten so expensive that leftovers represent a severe financial drain. Lately most of my paltry leftovers go as ground coats for bumpers and jambs to minimize the amount of new color needed. Gathering enough leftovers to paint a car in today's refinish market is at least about $500 of basecoat. But a similar idea would be to check the paint store to see what they have in the way of goofups or no shows.