So the San Fransisco trolly that you take in and out of dimensions is nice, but I have some suggestions to add some customization into the game. These can be purchased at the shop, but some with bigger price tags than anything. These options can be altered at a kiosk next to where the trolly comes in in the Bar.

Replacements for the trolly of different sizes. From similar trolly sized ones to smaller ones for sessions with less players.
Examples:

• The Bus model that's not used anymore but still in the files or more conventional trains to fit large groups
  
• Vans for medium groups
  
• Sports cars for very small groups
  
• Non-vehicles, like a box shaped object for one person (would likely come with an entrance/exit effect attached with it)

The crashing through the wall is a comedic and awesome looking effect, but it can be a bit harsh on computers. So for around the same or even more than the different vehicles, there could be alternate ways the transport enters and exits.
Examples:

• A swirling dimensional rift opens and the transport exits from it and the rift closes. For the exit, the rift appears again at where the transport would have crashed into, it enters and then the Void highway appears. It's basically the default without the wall smash.
  
• A callback to "Back to the Future", the transport arrives in flashes of light and skids to a stop. As it leaves, it keeps going until it crashes into something, then it disappears in a flash of light. Now 2 options can be avaliable to purchase: an instant mode, where the flash transitions to the Void highway like normal, or a cinematic mode, where the flash transitions to a 3rd person view of where the transport was about to hit the wall, where now only a lisence plate reading "JAZZCATS" and a pair of purple firetrails leading into the wall remain.
  
• For those "non-vehicles", they would likely have their own effects, with maybe some of the other effects compatible with them. One of these non-vehicle exclusives could be a "Bill and Ted" inspired one where the box comes up from the ground (or from the wall) then goes back in with an electrical storm, the void visible on the way out.

Welp that''s all i got. I know the "callbacks" may be just copying, but those kind of match the game's theme of dimensional travel.