As far as gear shift knobs, or emblems, we can do them anyway...your name, VW, Dichro, whatever you'd like. As far as duribilty on these, they would be just as strong as stock parts. (much more original
)Other parts would have to be tested, but I'm sure we could improve some things. Your ideas on things like this would be just that, ideas, until we could see them through. So use your imagination! Remember, glass is non-conductive so IT IS HEAT RESISTANT!!!! Diesel motors I'm sure shake the **** out of the parts, but metal parts break down, rust, as opposed to glass which is inert. If we could replace a part succesfully with glass, it more than likely would never need to be replaced again.
As far as dropping a wrench on glass parts, you would probably be S.O.L. Glass is durable, but not indestructable. I was thinking more along the line of a glass air filtering system. But to make any idea come alive, we would need to put our heads together.