This is a problem with all S2000s
 
The Elastic straps loose thier tension and no longer perform correctly.
 
Without removing the top, you can install these straps.
 
There's several 'How to Videos' out there but the general explanation :
 
The Straps come with two pins that locate into the rivot holes on your existing straps.
 
See the last Picture for refereance.
 
The straps will wrap around itself to hold it in place.
 
These are the nicest quality straps we know of.
 
Made by our friend Rizzll ( Maker of the storage bags too )