Mid year 2000 they went from the Koni 2812 race shock to the Dynamic race shocks and much stiffer springs. They are both prone to leaking earlier than most street shocks. The nice thing about the Koni shock is that it is still manufactured, not sure if the Dynamic is still currently available. The negative to the Koni shock arrangement was that they would make a clacking noise when driven on bumpy streets. It's my opinion that this is a combination of a short spring height vs. shock adjustment for proper ride height. The spring unloads over severe bumps and bangs against the seat. The Dynamic shocks were apparently much more difficult to dial in as well as excessive spring rates. Most individuals changed out the springs for better street as well as track performance.
Other than the obvious change to ABS in 2001 that's about it. One other thing, the earlier ACR's had really nice looking Momo five point harnesses, unfortunately they had some sort of recall associated with them. The later harnesses were in my opinion a lesser grade harness. That said they didn't have a recall associated with them so go figure.
