Pros:
When it looks good it really looks good! Dark cars get really reflective and light colored cars usually just get bright. When you can get a reflection out of a light colored car it looks awesome!
Door dings aren't as visible on a light car as they are on a dark one.
Of course, there is the way that scratches and swirls don't show up as bad.
They stay cooler in the summer. They don't absorb as much heat.
They appear cleaner at a distance when they really are dirty. Things like dust and water spots don't show up quite as much.
Cons:
Bugs. Man, they show up a mile away on a white car's bumper.
Harder to see if you have a product fully buffed off or not.
Since they look cleaner longer sometimes people don't wash them as often as they should and they get this black film all over em. They oxidize and people don't notice that either. It sure makes an impressive "after" picture though.
You can blind yourself washing them sometimes. White cars are really hard on the eyes if you are in sunlight.
