I found saloon used in The Reluctant Colonel with this meaning. I didn’t think about it much, other than, that’s weird. After finishing the book, I looked it up. Saloon can mean sedan (normal car) in the UK.

I just ran across this again, this time in Artemis Fowl.

Upon reading this second occurrence, I searched for the etymology of this word. (I don’t own an OED.) While I did find a few etymologies of saloon, none of them mentioned this definition.

So now I’m hoping. Can you help me, please? Tell me, how did this happen?