I'm not sure if this glitch is known or not , but it's a pretty entertaining one. Now what had happened was that I was just playing around with the new content and I switched from the ambulance to the taxi. Next thing I see (from the taxi's POV) is the ambulance gaining speed and moving on it's own! I don't know what caused it, but I just knew I had to figure it out. So after several attempts, I realized that the last thing you're doing with the vehicle stays as a command when you switch vehicles using TAB. For example, if you're holding the gas and turning right, and press TAB, the car will continue to turn and act as if the gas is still being held. No AI was involved in this either. I just knew that I had to have fun with it! I'm in the cab just sitting there and watching these four spin.
This isn't a glitch ( well if it is it's known) because in Nadeox endless highway or whatever he said it's fun to do this