Moderator: Hawaii-based airlines & Hawai'i forums
Join Date: Mar 2003
Location: Ka ʻĀpala Nui, Nuioka
Programs: NEXUS/Global Entry, Delta, United, Hyatt, IHG, Marriott, and Hertz
Posts: 18,037
This is answered in the wikipost:
Q. What is the minimum booking class to be eligible to freely select cars from Ultimate Choice?
A. You can book anything other than an Economy (A), Compact (B), or Manager's Special (EXAR) vehicle, and be eligible for Ultimate Choice.
Q. What if I book a Luxury/Prestige/Adrenaline car or a Minivan/Truck/SUV?
A. You will be assigned a car from that class in a marked space. You can either accept it or chose a car from Ultimate Choice.