How can I create a vehicle building script?

I can't think of a way to script this like I want.

Summary: Each player owns a base. Players can only build on their base.

Each part has an owner of who placed it.

Players can use parts to build working vehicles. For vehicles to function, they must include an engine, control panel and a fuel tank.

All the parts must be connected to the vehicle.

How can I detect if a part is touching a vehicle? Each separate part does not touch one another, but must be connected to a part of the vehicle. For example, if you built a large boat, the engine could be 500 studs away from the control panel.

I asked this before and someone suggested using distance. This won't work as it doesn't sense if the parts are in the same vehicle.

Where can I start?