When I'm accelerating my MY98 at 2500-3000rpm the revs seem to slip upto 4000rpm but the car only accelerates a little.a second later or so the revs drop again and the car pushes forward. Is my clutch on the way out or what could be wrong? I only have 40000km (2500 miles)

 

When a clutch is on it's way out, it's most likely to "fail", or struggle at the point where torque is at it's peak. On a UK car, this would be 2500~3000rpm.

If the car has been modified, and the boost turned up, try reducing it, and see if the problem goes away.

My clutch started slipping at 10,000mls, and a few mod's(STi). Just gave the old clutch to a friend (UK car) and he's very happy with it, doesn't slip at all.

Mark.