Cooling (Radiators especially prone to cracking more so than the expansion tank--replace both to be safe) actually, replace ALL cooling components.
Suspension (usual FCABs, shocks will be dead if they are original)
RTAB pockets (Check these for cracks)
Rear shock towers/Front shock towers (Check for cracks or mushrooming--S52 cars less prone but still check)
Oil pump nut (Like the M54, susceptible to undoing itself usually under track conditions)
Other than that, rock solid reliable car.
No more pimpin' and posin'. Time to do full professional maintenance.