you shouldn't get tapping when driving only when starting, according to the owners manual. i get tapping for only a second when starting from cold first thing in the morning never when drivng or when starting warm.

i've been told this is completely normal like the manual says and what other people have told me who have had the same noise since there cars were new.

i've heard the noise while driving could be the o-rings in the sump need replacing, do a search on the subject.