The initiative, claimed to be Roadside Services' biggest product launch in 15 years, is designed to differentiate the AA from rival services.
The company has agreed a deal with DaimlerChrysler to create a fleet of AA-branded Smart cars for the replacement service.
The offer, which will be available to all members free of charge, is being promoted through a £5m campaign created by integrated agency Rapier.
TV advertising begins this week and informs consumers that the AA will 'fix your car by the road or get you another one'.
The 40-second TV ad makes it clear that, while a free courtesy car is an important benefit of membership, the need to resort to one is uncommon.
The AA claims that it fixes eight out of 10 cars that have broken down on the roadside.
Rapier manages the AA's £50m financial services marketing business. In January it won the company's £20m breakdown and roadside services account, previously managed by EHS Brann.
M&C Saatchi, which is responsible for the AA's core advertising strategy, was not involved in the latest ad campaign.