....This is really bothering me because having a crispy crusted pizza is one of the main things that I enjoy about my pizza. Is it the fact that I'm getting into a cold car with a hot pizza? I don't know but if anyone has any insight on what may be causing this to happen and how I can stop it from happening I would greatly appreciate it.
I'd like to pass on one of the best tips I recently received from this forum
in regards to reheating pizza that should also apply to your situation.
HOW TO GET CRISPY BOTTOM CRUST FROM LEFTOVER PIZZA
1.) For frozen or cold pizza, first microwave a slice just until it thaws out and
the cheese begins to bubble around the edges. If the pizza is already warm,
skip to step 2.
2.) Use an ungreased teflon frying pan with heat set on medium. Place a slice
onto the hot pan and from the moment you hear that sizzling sound, continue
heating for 60 to 90 seconds. Lift it to check the bottom for burning or doneness.
3.) Remove from pan and serve immediately.
As you bite into the slice you wil get that mild crunch sensation of a
crisp crust. Mmmmmmmmmmmmmm.

This method will do wonders to revive thin crust pizza that has become
limp and soggy from being frozen or setting too long. Pizza with thicker
crust is less prone to this problem but will also benefit from this frying
technique.
This frying to reheat trick is absolutely the best tip I've come across in months.
When I make pizza I usually make about 3 to 6 pies and freeze them, then I'd
reheat using the microwave first and then the toaster oven (set on toast) to
crsipen a bit. HOWEVER, frying to crispen is much better than the toaster oven,
especially when the crust has become a bit soggy or lump.
So Upstate Pizza, try frying the slices just before you serve them.
It only takes about 1 minute per slice which makes it very practical.
PS: I forget who on this forum orginated the "frying to reheat"
concept, so please be all means, step forward and make your
claim to this fantastic idea. I thank you!

---pete---