Hello all my Evo sporting has developed a knocking rubber creak at low speed over speed bumps. Just passed mot and shocks look ok. No oil etc. Doesn't make any noise if I push down hard on the rear bumper when stationary. Could it a be a sign of rear bearing failure or just rubber bushings needing some grease?

Silicone grease

Remove rear springs and grease the spring rubbers where they sit against the chassis and rear beam