I almost never change my diapers in a multistall restroom. Especially the busy ones like you find in airports. There are always better options such as the family, unisex restrooms that are becoming so common in malls, large department stores and public places like airports.
At the mall, I always change my diapers in the unisex restrooms. Several of my favorites have a large granite diaper changing counter built into the wall that is strong enough to hold me weight and large enough for me to comfortably lie down. I always get excited knowing that hundreds of infants have lain in that exact same spot getting diapers changed just like me.
If I am feeling a bit risky, I like to stay in the room lying peacefully on the changing counter until I hear someone trying the door handle and sometimes then knocking at the door. Once that happens, I will quickly put my clothes back on and leave the family restroom never knowing what is waiting for me outside the door. About half the time I discover that whomever was knocking has either left or just used the ladies restroom instead. But the excitement occurs when it is a mom impatiently waiting for me. Some of them don't act very upset while others give me a dirty look which I don't respond to. But then there are others who feel obligated to complain and tell me that I shouldn't be using that restroom. The first couple of times I just slinked away but no more.
If the woman doing the complaining has grade school children with her, I just tell her that 'some people have special needs that aren't obvious' and leave it at that since I don't want to involve children. But if the woman has only a small infant or toddler, I quickly pull up my shirt to reveal the disposable diaper that I have made sure is several inches above my waistband. I'll follow up with telling her something along the line that I was in there doing the exact same thing that she is getting ready to do with her child.
The look on the faces of these women when they are that I am diapered is priceless. Most of them apologize, a few just get quite and ignore me. But not once has one of them complained or assumed that my diaper wear was anything but a medically necessary condition. I always leave my wrapped up and used diaper at the top of the trash can and have always wanted to see their reaction when they see it and realize just how wet or even messy I was.