Some people are having serious trouble finding the car nodes built in the room, and then some of them think the room is faulty.
I'll explain how to make them work.
Any car node in my room is exactly like any other furniture node -- you can put ANY furniture item to them, there's no special cars or anything like that, they work with ALL items. The only difference is that they are animated, they move around in the room.
Here comes the tricky part. You must NEVER do any sliding with furniture move tool (e.g Ctrl+move) nor rotate the car manually, or else you will get lost and desperate. ALWAYS move the car without pressing anything like Ctrl or Shift. Once the car snaps into place you can enter the trigger word and see if it starts moving. If it doesn't, then enter the stop trigger (important!) and try moving the car again with the move tool. The car often rotates itself when it snaps into place, then you'll also know it's on the right spot.
I have added guide images that show where the driving nodes are located.
Due to very limited time I'm unable to personally come to every room and show and explain, that's why I created this page here. I may update it if/when it's necessary to add more information.
Good luck! :)