Creating the Tram Interior
On the inside, I used the Append to Polygon tool and the extrude tool to create a surface inside the carriage for the interior.
I have finished the creating the inside walls/ceiling/floor of the tram. I mainly use the append to polygon tool to create the inner walls. This tool was useful for creating inside walls from the window ledges and the sides, but I noticed that at the front and back of the tram this tool didn't work. For these areas I selected the edge and then extruded it to the area I wanted it to cover.
I ran into some problems doing this: I ended up with some triangles and had some vertexes that I didn't need. To rectify this, I am looking at each edge and fixing any problems I come across. To make this easier and less time consuming, I have cut the model in half. I will fix the problems with the half that is left and then mirror it across.
A problem I came across when I halved the model is that there are a few edges left that won't delete.
I found that these wouldn't delete if I selected them and tried to delete them as they are, but when I selected an edge and then used the move tool, I found that they had hidden faces. By selecting the edges, using the move tool and exposing the hidden faces, I could then select the faces and delete them that way.