Delay AAA or BWC membership until incident?

[Lifeblood]

 I have read some of the older posts about AAA and the Better World Club as I contemplate renewing my mother-in-law's AAA membership. I was thinking of not renewing, with the idea that if we find ourselves in an incident where we want their help, we call at that time and set up a membership on the phone. Thus, if we have no incidents, we have paid nothing. Any disadvantages to this approach?

[Kazak]

In some areas, you may not be able to sign up for 'same day service.' If you can, there will most likely be a higher fee for that same day service. I recommend looking into that first.

[Ohio Teacher]

I use the sign-up when you need them approach.  At least in my area in Ohio, this is permitted.  That way you get a year of service from the time you need them for about the same price as the tow would've been, and you don't pay for the service beyond that.

[superone!]

I recently had this happen to me. I decided not to re-up my AAA until something happened... and then my radiator cracked halfway up a mountain in the middle of nowhere.

Having an older car (1977 mercedes now, previously a 1988 VW) that I really only use for out of town trips means that I usually cough up the $ for their "premier" service that gives you one 100 mile tow per year.

Well I didn't have any trouble signing up and getting same day service for the regular service, but if I bought the premier I couldn't use the extended tow for seven days. So I ended up buying the regular service and getting towed to the closest repair shop rather than the 60+ miles home. 

[AMustachianMurse]

It depends where you are from.  I am from Cali so If you have a rock-solid car here and drive primarily within 10 miles of home/your mechanic, then waiting till the same day is fine.  I recently had to find a way to get a car 25 miles away and looked into AAA to do the job.  It turns out, at least in california, you can only sign up for the regular membership which is $40/year, which only allows for up to 7mile tow.  You have to wait 90 days to sign up for the premier service which will allow the 100mile tow.  I asked the guy if it was so people didn't abuse the 100 mile towing service like I am and he laughed and nodded his head. 

In the end $100/year is not very much for peace of mind knowing i can get my car, or any of my friends cars that I am a passenger in towed for 100 miles for free.  I can certainly find the $8/month to cut out of my eating out budget, or going out budget, or gas budget, etc. every month.   
Just my californian 2 cents.