GoldLeader

How about a refrigerator? I understand that was the plot device in the original, possibly more adult oriented script to BTTF. It was reworked a couple of times and presented to different movie companies before the car replaced the fridge.

They moved the fridge to Indiana Jones and the Crystal Skull Vodka.

How is it, the gateway to Narnia is through the closet? While that isn't time travel it is escaping to another world. Of course you have the rabbit hole Alice falls through etc if one lists all of those plot devices regardless of what they achieve.

Actually there was a Swedish movie about time travel a couple of years ago which used the metro as its plot device. A guy stepped onto the metro and traveled some 35-40 years into the future, namely from the early 1970's to modern times, and then grabbed the same metro to travel back a couple of times, even bringing his future girlfriend back in time. The plot in that movie was that the guy had a heart failure which was terminal in the 1970's but in the 2010's it could be cured by an expensive surgery, so he found a way to secure a little money in his own time, so he could travel into the future, grab the money that had been growing for 30++ years, have the surgery and then possibly get back to his own time again and be able to live rest of his life.