I booked and Audi A6 at IAH from December 29th until January 6th, and yesterday I was trying to change it for the Cadillac STS (because of the V8 engine), and I found that the Audi A6 is no longer listed. I checked the Prestige Collection list at Houston and I found that there are only available the Cadillac STS, Lincoln LS, Hummer H2 and the Lincoln Navigator.
Please I need your help I want to know which car I'm getting instead of the Audi A6 or if I have any possibility to get a Cadillac STS.
Does anybody know why Hertz is doing this?
Thanks in advance

Sergio Maruri