Just putting this out there since it was mentioned in another thread but if you are at an airport that has National, try using this rental code from Car and Driver Magazine, XVC1092, and it waives the underage fee, and usually gives you a nice discount on the car. I've used this before and generally end up paying between 40-50% of the "list" price of the car. There are some restrictions on how many days but it's worth trying.
Hertz has this code: 1911795 . I've never used it but it waives the underage fee too if it works.
http://www.fatwallet.com/forums/travel-discussion/790643/ Not all of these still work but they are worth trying.
Hertz has this code: 1911795 . I've never used it but it waives the underage fee too if it works.
http://www.fatwallet.com/forums/travel-discussion/790643/ Not all of these still work but they are worth trying.