A bridge-builder-type car editor?

I have started working on a car game with buggies, because I think they're pretty cool. I have an idea: a 3D bridge builder-like car editor. (You can play an online 2D-version here) You can probably imagine: buggies are made of pipes and metal plates, where the pipes would be the planks that the bridges are made of, the points where the pipes cross are the joints, etc.
So, my question is: How to do this? I don't need code, but I would be very thankful if you would give some ideas or examples of how to implement this. I am pretty new to programming so this may be a stupid question.
Thank you!