Just thought I'd bring this back up.  There was a Taco Cabana thread on 
http://www.thefiringline.com.  A few months ago,  I visited one local Taco Cabana, and there was nothing on or near the entrance.  On a board near the menu, where they post their food licenses and such, there was a non-30.06-compliant "no guns" sign.  I wrote to Taco Cabana via their contact info on their website telling them about it, but not specifying which location.  I wanted them to have to check them ALL and figure out which ones are posted incorrectly.  I got a reply, and I wrote back, including my phone number.  I actually got a call from a Taco Cabana representative, and, while being very polite, I disagreed with their policy, and told them that their signage is useless.  She thanked me, and offered a gift card from them.  I told her that while I wouldn't go in a Taco Cabana that's properly posted, I might run through the drive-thru.  I got the gift card ($25), and have since visited two other Taco Cabanas, which were also improperly posted.  I went in, ordered my lunch on their dime, and ate - all while carrying.   
 
 
A not-so-humorous thing happened a month or so ago:  A guy was shot to death while waiting in line at a Taco Cabana somewhere around Dallas I believe.  I copied the story, and sent it to the Taco Cabana rep, and said I guess their drive-thrus aren't a safe place to be, either.