[mickchick]

Alamo's bigger branches only keep their cars for six months, but some of their smaller franchise operators keep theirs for a year. It is possible that a hugely busy Alamo like the one at MIA will have a few older cars in stock - say for instance] a customer has rented an older vehicle from a small Alamo office in another location but dropped the car off at MIA - but it is unlikely. As for choice, obviously no-one can possibly say how many vehicles will be available at any one time.