" in a pinch, you could always ask another motorist to put it on their card and just pay them the cash"

This happened quite a bit actually. The credit card "pay at the pump" was all that was available in some cases because some of the stations closed the convenience store part and locked the doors due to shoplifting and irate patrons. Things got ugly so they took sensible meaures to protect themselves. People still got gas, but couldn't get twinkies and beer!