Through August 31, you can earn 3000 American miles on a 1-day rental or 5000 miles on a 3-day rental with Avis. Use coupon code MUAA035 and provide your American Airlines frequent flyer number with the reservation.
A 1-day rental with Budget earns 1000 miles and a 3-day Budget rental yields 3000 miles. Use coupon code MUAZ025 along with your American AAdvantage account when making the reservation.
Based on my experience with past offers of this sort, you do not need to use the discount codes that go along with this offer, which may or may not provide a decent rental rate, in order to earn the miles.
Rentals must be from participating airport locations in the U.S. or Canada, and begin by August 31 in order to be eligible. The offer details page does not specify which airport locations are not participating.
And don’t forget you have a ton of options to get cash back or points for your Avis rentals as well.