I had to drop someone off at SFO with the van today. According to this page: http://www.flysfo.com/web/page/parking/payment
They have clearance for 8'2" vehicles. Quick measuring suggests that my van is 8'1.5" to the top of the (RV roof) AC.
I had been in there recently, and generally have had no issue finding parking on the first level, and knew that there was plenty of space to the ceiling, so I tried my luck: Driving in, I barely bumped the height check. I went on assuming that that meant that I just needed to be really careful.
It turns out that the gates lift up and over the vehicle, so that's the next place for concern, but pushing it up with my hand as I drove through seemed to be good enough. The next obstacle are numerous signs that are hanging down and look rather scraped up. I managed to carefully swerve around them, but had the feeling that I might be just tall enough to hit them. Same story again with the exit gate.
So, I pulled it off, and would do it again if I really had to, but would not send anyone else in there with the vehicle. I'd also avoid it if I had another choice. Even in this case, I could have just done a curbside drop-off, which would have been fine.