Have you ever seen a movie about a haunted/possesed blue car?

I saw this like, years and years ago. A woman had a blue car, it looked a bit like a Volkswagen, maybe that’s what it was. Too long ago, I was little and I don’t rightly remember.
For some reason I keep thinking the title was ’‘Christine’’, but I’m also well aware, I hope some people know by now…of Stephen King’s Christine with the big red car. That’s not the movie I’m thinking of though. (even though it’s awesome)
One significant part I remember is that when the woman turns off the inside light of the car, a strangled, breathing sound is heard from the back seat. When turning on the light, the sound stops. She tried to sell the car away, but everytime someone wanted to test it, the doors would remain inexplicably locked. It’s an old movie, either from the sixties or seventies, I’m guessing. Can anyone help? What is this movie? And don’t be showing me ’‘The Car’’ trailers…even if I totally wanna watch that, too. XD
I’ve been trying to find stuff about this online, but nothing is coming up about this movie. Help? And thanks.