There is a way to cut the cab corner windows that are tempered. Tempered glass is glass that has been heated up to near melting then cooled very quickly, so that the outside of the glass becomes solid before the inside. The outer layer is squeezeing the inner with great pressure. The only way to releave the pressure is to slowly heat up the glass (which could cause the glass to burst anyway) to almost fluid then cool it off slowly. Once cooled it will no longer be tempered. You can then cut, drill, etch, the glass without problem. Then have the glass re-tempered. But the glass might break, because the older the glass the harder it is to work with. I have never done this but my frien, who is a professional glass guy passed along the info. He dumned it down to explane it to me, so the process could be slightly more complated, and is beyond most of us anyway.
Hope it helped
