An in game vehicle creator would let you make vehicles in game, as the title states.
How it would work: certain parts of a vehicle would add certain abiliteys. If you would like to make your vehicle go faster you would add faster or more parts. For instance, if you add a set of wheels the vehicle would have a speed of 1, if you add another set of wheels it would have a speed of 2. in the IGVC(in game vehicel creator) you would only have a certain amount of points you can use for creating your vehicle to not lag the server up. If you would wanto, you could add normal bricks to your vehicle to make your design more creative. Your vehicle would be built on a IGVC brick so it wouldnt be confuesed with other bricks.
To make your vehicle, you would hit b, go look for the vehicle tab and add parts to it. you build your entire vehicle on the IGVC pad as mentioned earlier.
I dont know if this is even possible or if it is, how long it would take. I think this would make this game a lot more fun and more enjoyable.