Solid display problem + auto cleanup

I have set my scene in potato mode so I can see the textured planes that I use instead of image planes. Because my models aren’t textured, I display them individually as solid. But the model I’m working on just stopped showing as solid in object mode. It displays fine in editmode. Here is a screenshot:

Notice that the active object (the car - or plane.002 as I haven’t named it yet) is set to display as solid and yet shows as wireframe. The cube next to it has the same settings but displays correctly as solid.

Another thing I was wondering about is if there’s an easy way of getting rid of vertices/edges with no faces. Sometimes I find I have loose edges and vertices that may have come about by accidentally clicking ctrl-LMB or extruding and it would be handy if there was an automatic way like a script to remove them.

Also an easy way to highlight triangles in a mesh. I model mainly in quads because I use subds and on complex models, I find it hard to find triangles so that I can try and change them to quads. If there was a way to highlight triangles again maybe in the form of a script, that would be very helpful.

I just discovered a script in the scripts list that cleans up meshes. Go to script window, scripts, mesh, cleanup meshes.