The little pulley at the top of engine for the supercharger , might be the idler pulley? its the small one at about the 11 oclock posistion left front top area,my 01 L only has 4500 miles on it ,but there are grooves worn in the pulley,you can feel them when you run your finger nail across pulley,don't know why it is doing this,since the back side of chareger belt is all tha makes contact?

 

nothing to be worried about, every lightning i've seen has them