Hehehe, of course I have
Have you ever tried the 'ride as passenger in an ordinary car ' trick?
It takes some luck and preparation, it doesn't always work either;
Steal 3 cars and park them alongside the road so you have quick access to them. (already hard to do without a cop noticing)
Take the first car and block an oncoming car by parking in front of it, take the second car and use it to block the drivers door, take the third car and park behind the car so it can't back up. You'll need to do it fast!
Then highjack the AI driven car at the passenger door side. Because the drivers door is blocked,(and stays blocked because the driver can't back up either) you won't be able to push out the driver, so you'll just sit in the passenger seat. Now wait for the driver to become fed up and go into road rage mode and starts pushing it's way out, and voila, you're driving along with an AI as passenger.
Unfortunately it doesn't always last too long as the enraged driver will overtake recklessly and ignore red lights, so they usually end up smashing themself unconsious somewhere, though do it at the start of a long freeway stretch and you might be in for a nice wild ride along. :lol:
In online mode it's easier btw, since online allows you to enter the rear seat (with other players normally). Just use two cars to block both front doors on a 4 door AI car (put m in V shape to block the forward movement a bit too), then you'll be able to enter the rear door and ride backseat because the front doors arent accessible (or do the same with an AI driven ambulance, and enter at the backside)