Underside colors - why do some match car color?

[JoeGrapes]

Well, 15 years ago I had a 1974 Barracuda that I used as a parts car. The color of the car was yellow. The bottom was sprayed with heavy black under coating. I scraped some of the under coating off to see what was under. The bottom was painted yellow just like to top. So when I painted my Gran Coupe I painted the bottom the same as the top and only sprayed under coating in the wheel wells. And I know that 74 was original.

[JoeGrapes]

Oh, and the inside was also painted yellow like the outside. Either way, painting the bottom the same as the top is more work but it sure looks a lot better than under coating. You will be glad you did even if the factory didn't.

[PlumCrazyRTSE]

Any paint shop can shoot a car all one color, that's an easy task.  It's much more difficult to paint it correctly by reproducing what was done at the factory.  If you put your bottom painted car in a judged show, in the original vehicle class, it will lose lots of points if it has the bottom painted the same as the top.