Referred to Wilson Er from fellow Merc owner. Sent in my car to troubleshoot 2 issues.

Wilson advised me to rectify and then monitor on my 1st issue which is likely to be engine knocking.
For my 2nd issue, the mech Ah John and his fellow mechs tested my car to troubleshoot. Found out that my drive shaft is totally dry and might have caused the problem. Thus they advised me and then rectified the problem in the most cost efficient method and the problem went away.

Gives a lot of confidence that Wilson himself is a Merc owner and knows the common Merc problems as well :)

Good service and very friendly workshop. Very expert in conti and japan cars and brakes.