Active changing and viewing of materials

I’d like to know how to view the way an object with textures will look before the actual rendering (if any way possible).

and also, i’m modelling a car, and i cant get the windows to be transparent without the rest of the car being transparent. any suggestions?

thanks

1). Unless you use UV editor assigned textures and use TexFace you won’t really be able to do that. There’s shaded mode but that’s only per vertex.
2). The answer is simple, give the windows a different material index.

  1. Shift-P for a preview window (grab lower right corner to resize it).