Got in the car, started it up, put seat belt on and went out of the parking lot onto the street. A sound like the seat belt alarm went off but the passenger side sliding door opened as I drove on the street...

I went into another parking lot to shut the door & tried it again in drive gear & it opened & I tried reverse also. I never touched any of the over head buttons...

DANGEROUS. if some one was in the rear seat at that time... A few years ago doors were closing on my passengers getting into the rear seat. This happened a couple of times...