The other cultural thing you just learned here is that "rapide" doesn't necessarily mean "sans RDV" (i.e. no appointment needed).
It has only been in the last 10 years or so that hairdressers "sans RDV" have become pretty frequent here in France. But the quicky oil change places here (like Speedy or Norauto or Feu Vert) do tend to have ways to book your appointment online - which usually means you can get an appointment for the next day. By French standards, that is pretty quick.