I only rendererd with GI, FG, RT, Caustics
If there was a HDR map for IBL, then there were not black reflections, as you sad right!

Thats a matter of argument to think about an environment map!...

Yes it is completely Glas!
I was wondering about the black parts too, but I catched me a Glas (in real world;)) and made a scene like the CgI and I saw the black areas too!!!

probably there are...

Hello at all!! :)
I have downloaded the rc car and thought that I probably can bring it into a scene...
Thats my work for now! What do you think?? C&C???
Probably you can tell me what I did wrong...