Hey Panel,
How did you create that lip ?
Do you have a pic of the whole bus, like a 3/4 front/side shot, I guess it would give a better idea if we can see the whole roof line.
Anyway, I agree that although it looks good from the front, the difference with the sides is too big. I don't think rocker extensions will look good.
I'd paint it first, the same as the body, just to see how it looks. Maybe if you taper the ends towards the wheelwell (not sure if I describe this properly)...
Anyway.....that's all of my brainfarts for now....
Rob.