I had a '01 S60 2.4T (which my daughter has now. In '01 the auto tranny had a feature that puts the tranny in "neutral" mode when at a standstill so when you take your foot off the brake to start forward the tranny must engage from neutral to direct drive again. In normal driving chances are you would not even notice it but if you start agressively there will be a momentary lag until the tranny couples up. This feature was only found in the '01 models and was discontinued for the following model year. Don't know for sure but I read that this feature can be disabled through a software download. Check with your dealer on this.