Originally Posted by
Corey
It could be safe if the surface is not 160F which it can be in the sun depending on how long it has been in the sun and what color. There are so many variables it is difficult for us to tell you "yes its ok" and then find out it takes a horrible streaky turn for you because the paint is stovetop hot. I would recommend trying carefully at your own risk on one panel... cooling with water first, then applying the product via a wash mitt, immediately rinsing carefully, drying. and inspecting carefully before moving on.
For sure it is possible to do safely in sun but it depends on the sun, car, humidity and how long you leave it on, etc.