Pop out quarter window question...
 

When did Porsche originally offer the pop out quarter windows on the coupes?
Is the frame and hardware different year to year or are they inter-changeable?
My guess is the only difference might be the slots in the back of the B pillar where the two front brackets bolt up?

Thanks

Speedo

This is not a definitive answer, but based only my limited experience with early 911s.

I believer they were offered from the first production year since they were offered in the 356. AFIK, the windows should be interchangeable since the dimension of the opening did not change throughout the years of production. I'm guessing that the mounting slots also did not change either, but someone with first-hand knowledge will confirm or correct.

The shell is ready for pop out winows, up to *at least* the 964. In the 964, however there is one layer of metal to be peeled away and the slots have to be cut, but the inserts are there. Very good thread on rennlist 964 forum about that.
Useless trivia: the factory cabrio hardtop also has provisions for popouts.

I had to remove the extra metal to expose the slots on my 76 .

You will find everything you need to know about pop outs here: http://forums.pelicanparts.com/porsche-911-technical-forum/347620-install-pop-out-rear-quarter-windows.html