At all of the stations I've used in Colorado the adapter isn't needed, although one was "bent" and needed to be turned, as described by ChuckG. On a trip through Nebraska a couple of weeks ago the pumps were fine everywhere except for Lexington, where the nozzles at two different stations were either too big or too small. I've seen them being too big when fueling my diesel pickup, but even those could be used so long as you "managed" the high flow rates that some of them have. Being too small wasn't a problem on the truck as it didn't have the door like the X5.

Back to Lexington, the X5 was filled with luggage and the extension was somewhere in the underfloor storage. It's always fun to unload everything when it's 5-10 degrees F and windy! The extension worked well enough, and at least on those pumps the automatic shutoff worked correctly. However, I still managed to get some diesel on my hands and couldn't quite get rid of the smell using the weak soap at a McDonald's.

Ah well, the X5 was getting 25 to 27 mpg, even in the extreme cold and with a headwind, so it wasn't like I had to fill up that often!