No upgrade fee on the Model 3--I was surprised as well, and actually thought it might have been parked in PC by mistake. But the key card was inside, and a staff member approached just to make sure I knew how to operate it, explain how the charging works (battery was at 75%, he just told me to bring it back with 10% charge or more), etc. The only additional charge I had was for charging once at a supercharger, which was around $20 for charging from 25% to 80%. That ended up being more than I ultimately needed, as I returned it at 50%. Nevertheless, $20 wasn't bad considering I drove around 190 miles with the air conditioner running the whole time.

I love flying in/out of BUR and am willing to pay a slight premium to do so unless I need to be on the West Side. The walk from the airport to the rental car facility takes around 10 minutes or so under an outdoor covered walkway. There are moving walkways as well. 100% beats having to take a shuttle and dealing with LAX traffic.

I can't promise that there will be a Model 3 in PC though!