How to make a STL car to a car with surfaces?

I am trying to make a cad model of a car . I like a car model but the file is in .STL format . I want to make that car 3 wheeler with roof. So i have to edit it, but in STL it seems impossible. Anyone who can help ?

1 Answer

Mesh data can be converted to surface data, but the result is not usually what people expect, or want.
This bust is a great example: Upset Lady
You'll see below the mesh data as it looks when converted to surfaces. The result is pretty random.
If this will work for you, you can try using Meshlab (free download).
Otherwise you'd want to use something like Geomagics Design X.
Let us know how it works out. I'll be back at my office in a few days and can try to convert the model to a surface if you still need it.