Who's wrong?

To an English-speaking person, "get off the car" would mean that the person was sitting on the outside (for example, on the roof); "get out of the car" would mean that the person was inside the car (on a seat, for example).

Cars you get in/out of Busses/trains you get on/off of

Location - at Surface - on/off Container - in/out A car is considered a container, unless you are literally sitting on it, the roof or the hood etc, in which case it becomes a surface.

Unless you’re standing on top of the car, it’s “got out of” but it’s “off” for buses, boats, trains, planes or just any public transit basically!

https://www.britannica.com/dictionary/eb/qa/What-is-the-correct-word-to-use-for-vehicles-in-or-on-#:~:text=Question,in%20and%20on%20with%20vehicles.

In Miami people say I got down from the car. Comes from Spanish.

Is she on the car or in it first?

*get off + a vehicle* = EXITING A PUBLIC TRANSPORT It is generally reserved for public transport. It is an expression for exiting a public transport. For example. *I got off the train.* *She got off the bus.* *We got off the ferry.* For **PERSONAL TRANSPORT** the correct phrase is *get out of* For example. *She got out of the car.* In this context, the car is usually a personal vehicle. **ADDITIONAL NOTES** "Get off" used with a persona vehicle, usually refers to a person on the outside of a vehicle (e.g sitting on top of the vehicle. For example, you see someone touching your car, you say: *Get off my car!* IN SUMMARY. (1) *get off + public transport* = exit/leave a public transport (bus, train, ferry....) (2) *get out off + personal transport* = exit from a personal vehicle. (3) *get off + personal transport* = someone is touching the vehicle from the outside

Perhaps her family could never afford a car with doors and a roof.

I have to stop myself from saying "Close the light" constantly I understand the struggle.

She's your girlfriend. Wouldn't she be best able to explain her unusual expression?

Get out of: the car, the house, the taxi Get off: the bus, the train, the plane, a bike As others have suggested, getting off the car implies the person was sitting on the outside of the car, on the roof, bonnet/hood etc

For the most part, if you can walk upright onto a vehicle (train, bus, boat, airplane, etc.) you get on and off of it. If you can't, (cars, mostly,) you get in and out of it. If my friend was talking a story and said they "got off the car" my assumption would be that they were sitting on the bumper or hood, or even just leaning on the car. I would not ever think they had been *in* the car.

You are possibly mishearing your girlfriend and she is actually saying, "I got off in the car". If so, you may wish to reconsider your relationship.

Getting off the car sounds like something a dragon would do

This is a calque from Spanish, which is particularly common in Miami English due to the prevalence of Spanish speakers there. You said she's Mexican-American so that makes perfect sense. It seems like most people don't know this given the comments are completely not mentioning the fact that this is a relatively common thing; I imagine most are non-American or just white.

Out

Phrases where you would use the word "on" you can use the word "off" I got on the train/ I got off the train. I got on the motorcycle/ I got off the motorcycle Phrases where you use the word "in" you can use the word "out" I got in the car/ I got out of the car I got in the taxi/ I got out of the taxi

Spanish speaking people do that I think? It’s the way it translates. Also if you drive over something you’re “stepping” on it. Used ro drive me crazy but now I’ve picked up saying “off” too, after being married to a Spanish speaking man for years.