The trick is to pick whatever is available - then you pick the class you want and ask them to get it. As long as you are an EE - you'll be able to select what you want. I did this on a 3 day rental recently, booked the most expensive/hardest to find car that was showing on the options. You can then tell them you have a special reservation and you'd rather get the other option. The classes won't change the price even if you get a 18-passenger van. Just don't go over the amount of days as you'll get tacked on with the large daily fee.