....If you are shipping it - How is your hot car any different than a hot UPS or Fed Ex truck? Bottom line is that if you ship beer in hot weather, it is going to get hot. No getting around it. It is not ideal, but it happens.
I try (as best I can) to look for a shipping window. where the weather is decent, and I can ship in a way that it will not sit over a weekend in a truck. Have to look at the time line you have - when do the bottles need to be there? Can you wait? Is it going to be better or worse temperature if you wait? Just gotta do the best you can with what you have for shipping weather. You can try to keep cool as long as you can, throw a couple ice packs in (in a ziplock) to buy a little more time, but in hot weather it is just not perfect sometimes.