Originally Posted by
sdsearch
Isn't that exactly what Avis Select & Go is? Except that it adds the ability to Upgrade (for a fee) in addition to Exchange (for free)? And except that it claims (not sure if enforced) to require you have reserved a midsize or larger to qualify? (I've never used National so I don't know how similar it actually is, but based your description doesn't seem much different from Select & Go Exchange is.
I do about 95% of my rentals with national and 5% with Avis the times it is cheaper or want a specific car class. With national you are not assigned a car and can just walk into any car in the aisle and be on your way. No need for contracts and etc. At the Avis I go to they never have any cars in there and even if they do its cars like a Mercedes E300 with a contract already.