[IYAS9YAS]

What idiots. I’d like to tell them my silver mini-van (about as reflective as you can get, due to the metallic paint) gets just as hot inside as my black Buick used to. The color of the car matters not.

[steve86]

I disagree: my white topped cars stay pretty cool, but I sure as H don’t think it should be law.

[smokingfrog]

I think the color of the car might make a slight difference, but there are many other factors as well. Your minivan has lots of big windows which let in the heat.
I have a light colored Mazda 5 which has a large, sloping front window, and it seems to be hotter inside than other cars I have owned. The interior is black/grey as well, which probably doesn't help.
I wonder if they make any cars with LowE glass? They would sell well in south TX.