Good luck. In my experience, even calling the local agency will not guarantee you squat.

Book the class of car you want (if you want the '11 Sonata, book a standard), and hope they have one available.

I usually walk the lot and see what they have on the lot before going to the AVIS desk. Of course, in smaller facilities, this is easy. In huge facilities (IAH comes to mind), walking the lot would take days. Then I write down spaces that have cars I like, then I request those cars, and when the agent says they dont have any of those, I give him/her the space numbers and see what they can find.

p.s. AVIS First means squat these days. I havent had an AVIS First upgrade in months.

p.p.s. I'm driving the '11 Sonata this week. While its decent, its nothing to write home about. I asked for one this week to see what all the fuss is about. I'll go back to asking for the Taurus next week. I guess it beats the Impala & the Maliboooo.