The Car is John's Dad's main mode of transportation. Inside it is John's copy of the server version of Sburb and a green box containing John's birthday present from Jade. In Act 2, Rose attempted to move the car closer to John using Sburb. However, her laptop's battery died, making her lose her internet connection, thus dropping the car into the dark cloudy abyss.
Jade apparently predicted this turn of events, along with a prediction that John will get it "when he really needs it."
As of Act 4, John has travelled to the Land of Wind and Shade, where it was confirmed that this is where the car has ended up. John heads to the car to retrieve both the server copy of Sburb and the present sent from Jade.
Before John reaches it, the car is found by Authority Regulator, who notes that the vehicle is illegally parked and removes the Beta and the present from Jade. The car is shown as being pretty smashed up, with smoke billowing out of it.
Dad carries a spare car in his sylladex.
The trunk of the car contains a vast storage of shaving cream that no one ever found