Answer:   The fabric is known as Codura, a Dupont fabric designed for back packs.

2.  Does the installation interfere with the windscreen option?

Answer:   No, not on a 986.  The windscreen itself sits on top of the roll bar, and there is space between it and the bar.  The straps do help to tighten the windstop from vibrations, but does not interfere with taking it off and on.

3.  What's the size difference between the large and small?

Answer:  The large is slightly wider (1") but mostly it is taller (3").  The extra height prevents access to the storage box, though even with the small bag the straps obstruct the storage box a little bit.

4.  Can you still use the center console bin?

Answer:  With the small bag it is possible to adjust the straps such that you can still open the center console bin.  The lid won't swing completely open, but you can still get inside.  It does prevent you from using the console bin as a cup holder location.

5.  Why might you need the extra two straps on the bottom?

Answer:  The bag is available with two or four straps.  The extra two straps attach to the seat belt receptacle on the Porsche Boxster.  If you carry heavy items in the bag, it is possible for the bag to swing forward with only 2 straps under heavy braking.  The 4 strap model will keep it firmly in place.  Most people only use the top two straps, unless they are on a race track!