Shock Knock Repair
It's a Shock Knock. It's a common problem with 4g and 5g preludes, often known as "shock knock." There are two separate "Technical Service Bulletins" that Honda has published about it: TSB #99-084 and TSB#00-090. Make sure your dealer reads both before working on the problem.
SYMPTOM
When driving over bumps, you hear a clunk noise from the rear suspension.
PROBABLE CAUSE
The upper spacers in the rear damper assemblies compress over time, causing excessive clearance.
CORRECTIVE ACTION
Replace the upper collars in both rear damper assemblies.
PARTS INFORMATION
Damper Collar (two required)

/N 52728-S30-004, H/C 6655195
1.2 hours labor.