Got just about 8,000miles on my vRS but hav started to noticeif the rpm is at about 1500 in fourth theres a strange grunty noise which soon disapears but this doesn't happen in any other gear. Not really that worried due a service soon and under warranty but wouldn't mind knowing what it is any ideas?

Is this under power or when you lift off the throttle?

under power thought it might of been because the turbo wasn't really going but only noticing it in 4th (first derv not totally sure how they run)

I can get this in mine in most gears. It has something to do with the dual mass flywheel if I am thinking of the right thing. Best to try and get the revs at 2000 when accelerating, gives better economy too.