I'm not sure how many others have noticed, but aftermarket is so much nicer to "correct" than factory paint. I tend to notice it mostly on black cars, but I'll often notice that a pannel or two buffed out more easily without buffer swirls/halograms, and then by using my ETG I can usually confirm that these are repainted pannel. I guess the problem is...when developing factory paint, the last thing manufactures consider is how easy the clear corrects/buffs. On the other hand, I think when the paint companies design paint for the aftermarket world, I think the correctability of the paint is of primary importance, as they know most paint and body shops are going to have to sand and buff after they spray.
Some of these factory blacks are a real pain to get swirl free.
Some of these factory blacks are a real pain to get swirl free.