No genius at all, just somebody that has travelled a small bit and (used to, don't drive anymore) always check on this particular thing. Mainly to see which association covers any carproblems in the country 'm going to, but also to check out possible perks. You wouldn't believe the many discounts and extras you can get at all kinds of places around the world when being a member of the right association.
Car insurance overhere isn't enough to be able to use the AAA-discount. (we can get a car insurance through ANWB -our AAA-, but without a full membership no discount). But then again, I don't know if NRMA would automatically throw in a AAA-membership.
My advice; call in asap when the rates come out. AAA-rates tend to come out around the same time as the new year rates are released or within weeks of that. When you call at that moment, you've got a great change of getting a AAA-rate. Not a member yet (if membership doesn't come with the carinsurence)? Become one!
Most of the times the prices aren't very steep to become a member. For instance; I payed about 35,- (about $52,-) for my membership 2008. I don't drive anymore, so it's solely for the WDW-discount. That fifty-something dollars has saved us lots. Rack rate for our 14 days at CBR would be $2400,- . Because of the AAA-rate (and a small 'extra' from the booking-CM) we're paying $1743.43 I'ld gladly pay $52,- to safe almost $700,-
So if anyone is travelling anywhere; always check which associations are affiliated to the one you joined! It can safe you a nice amount. Not only in the US, but also in Ozzie, Asia, Europe etc.