I just wanted to report back that MUAZ013 does work for 1000 AA miles per day.
I recently turned in a 10 day rental and 7-10 days later in my AA account I had two entries, one for 500 Budget base miles and one for 9500 Buget bonus miles.
1000 miles a day is a great deal for anyone who rents a lot of cars. It can be a little tough to get them to add the coupon # to your reservation, but keep fighting. It runs through September 30, 2012.