Originally Posted by
HKCH
Update on my question
BA was able to change my AVIS car booking on the phone and they did not charge me as this change was a fault of AA (changing my destination airport)
So, everything went well, happy customer again ;-)
As a tip for the future, making non-refundable reservations based on any airline's schedule (particularly AA's) 3 months out is probably not a good idea. Schedule changes are the norm, not the exception.
I'm glad to hear that it worked out for you this time, though.