I just received this email from American:
As the preferred car rental partners of American Airlines, Avis and Budget are proud to offer you even more for your rental. As an AAdvantage Platinum or Gold member, you’ll now earn a minimum of 1,000 miles for every qualifying (one day or longer) Avis or Budget rental.
They are also awarding an additional 500 bonus miles per day up to 2,500 miles per rental. No registration is required for either offer and eligibility will be determined based on your AAdvantage number.