Thanks for your fast answer!
I Ask the same question to a customer service guy just to now what they said about this.
here his answer:
"If you are asking that the wax would melt off the finish once applied and then exposed to hot temperatures, that is false. The #845 Insulator Wax basically has the same ingredients as the #885 Fleetwax except the #885 has a higher concentration of them. We sell a ton of each in the South and have no problems like the one mentioned.
Now maybe if you left the can in a mall parking lot all day exposed to the hot sun, then I would say it would melt.
I will go for insulator wax at least I'm sure that one is going to work fine. people suggest fleetwax but i don't want to take that risk