Wastegate chatter would be my guess, I'm not entirely sure what exactly it does, but it sounds like it keeps the turbo spooling like antilag!
Some fantastic driving there! I love the big flicks!
Dan
We all drive Scoobys for the same reason! I have this MonteCarlo 98 video somewhere recorded on VHS... I dreamed about having a Type-R every single day since... well after 11 years.. the dream's come true I'm a happy b*****d
EDIT: OMG I can't stop watching it over and over !!!