It came out around the same time as the movie Bully 2001. It had the same plot in a lot of ways. I do remember they stab or shoot him from the backseat of a car (through the driver seat). There was a girl there as well that was terrified
I’m trying to remember but could they be any of these bully-ish killing movies?
The Rivers Edge 1986
Red 2008 Red (2008) - Plot - IMDb
Dead Man’s Curve 1998