Don't worry, it is so easy to see when a person is more into vehicles than people. They seem to have little tiny hubcaps in their eyes, instead of irises, like the rest of us.
Call it a fetish. Most of us accept that as we nod and back away slowly.
Just like that!
What Car?? :-D :-D
When that human is around, start humping the car. She/he will get the message.