"Hi! Just letting you know, we will be able to make you a traveler for you but it will take about 20 minutes. If that's okay with you, we will charge you at the window, have you park in the lot, and we'll walk it to your car when it's ready!"

Whenever I walk it out to them, I remind them that they're more than welcome to call at least an hour before they want to pick up their traveler so they won't have to wait. And if they want it early in the morning, they can call the night prior and we'll be able to have it ready half hour after we open the next day.