hi
i am confused what you want to do?
a) make the car make bov noises?
b) fit a different bov?
c) make it flutter ?
if a, fit a pod filter, the std GTST already has a bov
if b, change the bov to a different one, just dont go for an AMTO venting one, that will make the car stall
if c, block the std bov off as Tangles has said, that will make it surge and flutter
the stalling occurs when using an AMTO setup, that is, you dump the bov'd to the atmosphere