The sound is intermittent, that is why it is so difficult. I though i should wake up at 6:30am, drive to changi and then back and reach TCM@BT by 8am and hopefully the rattling sound will appear after a long drive....
I think not worth the effort lor ... cau there is good chance that the rattling sound cannot be reproduced by TCM or yourself. Best is to get a workshop or TCM SA who knows to look into it. If not, will be a wild goose chase.
May I suggest you to give Steven of TCM Bukit Timah a call (dun quote me pls) to see whether he has come across this or not? If not, check whether some of the reputable workshops quoted here are able to help.