Ok, it's a bit of a twist on one of the AA's nomal offers (Free £20.00 M& Voucher), but I'm sure some people might find £20.00 free petrol me useful, especially people buying Breakdown Cover!
FROM THE AA WEBSITE: Price shown applies when purchasing AA Membership online. This is only available to new members for the first 12 months of cover, thereafter the renewal price will be the standard price (at the time of renewal) for the chosen level of membership. The offer is for a £20 fuel voucher and is available to new members only, who must join the AA online and pay by a recurring transaction arrangement. Allow 28 days for delivery. Cash or other alternative not available.