Dan - is the autobarn one the bosch one from the SAAB or just an average plumback BOV ? did u just quote the serial number or something?
helmann - without taking the BOV off, i think you can tell by listening for a flutter when you back off the throttle on boost, but from what it sounds like the stock BOV's don't last long so its a good idea to replace anyway, otherwise, it aint that hard to take off, just take off the three pipes and clamps holding it in place and try and blow through it.