Four years ago, I added Laura to my AAA membership.  I called, shared her information - including our relationship status - and paid the additional fee (same process as my Dad adding my Mom to his account).  We've used repeatedly over the years; she's used it more oftenn than I for travel purposes. 

So I was surprised to learn that AAA South just recently added Family memberships to married LGBT couples (not domestic partners - yet).  Apparently, the regional AAA's make their own policies with this regard.  Here's the statement from Equality Florida which is served by this branch of AAA.

Icon of America's Roadways Recognizes Marriage Equality
In Meeting with Equality Florida, AAA South Pledges Family Memberships to Same-Gender Spouses
During a face-to-face meeting yesterday between Equality Florida and AAA South, top management at the 4th largest AAA affiliate in the country committed to recognizing all spouses, regardless of gender or sexual orientation. The policy allows gay married couples to receive spousal discounts under AAA's Associate Membership program.
Equality Florida launched conversations with AAA several months back after receiving calls from gay couples who had been denied family memberships.
?We had not talked about this issue very much at all until you reached out to us, and that has caused us to talk about it quite a bit,? said Tom O?Brien, President and Chief Executive Officer, AAA Auto Club South. ?Our policy does include gay and lesbian spouses, wherever they were married. Whether in other states or countries, they qualify."
AAA South management says it will take about 2 weeks to train 3,000 staff members to implement the policy uniformly.
  
Same-sex couples applying for a membership need only state that they are married to receive the family benefit.  Management also left the door open to expand the policy to include domestic partners - gay and straight.
 
AAA South has more than 4 million members in Florida, Georgia, Tennessee and Puerto Rico.

So, you can see where this is going.  Southern states + support for gay families = fundies spilling out of their pulpits.

A sample advocacy letter:

My family and I were appalled to learn that AAA South has bowed to the demands of a homosexual extremist group by offering Family Memberships to same-gender spouses.
81 percent of Tennessee voters, 76 percent of Georgia voters and 62 percent of Florida voters approved constitutional amendments that define marriage in their state constitutions as only between one man and one woman.  The AAA South policy contradicts the law and public policy of the states in which the company operates.  
Furthermore, a policy allowing same-sex couples to only need to state that they are married in order to receive Family Membership further tramples on the institution of marriage.

I was fascinated to learn that if Laura and I relocated to these states, we would lose our family benefits and have to purchase individual policies.  We went to AAA to have our City domestic partner affidavit notarized when we applied for domestic partner benefits.

Which brings me to one final point.  When it comes to domestic registries for the City or to receive State benefits, why not count other official acknowledgements as one type of proof of the relationship?  For example, if I want to sign up for the City registry, why not accept our AAA domestic partnership acknowledgement as one of my forms of proofs?  Wouldn't that be a way of legitimizing corporate domestic partner efforts?