dhacker:

My brother had that problem. People under 21 are basically excluded. He e-mailed Guy Booth wanting to substitute more flights for the car rental. He wouldn't budge. Thrifty will rent 21+, Avis 25+. He is going to have his father post a rental on his LP account. It should work. He's had his father's Hertz rentals on his DL account in the past.