Oil and filter change

my local Halfords now stock bike filters and had one for the Millé
and once again i have used 15/50 Mobil fully synth car oil which comes in 5ltr's as the Millé takes 4.5
it is 2000 miles since i last filled the Millé with the Mobil, the first time i have used car oil and i noticed there were no bits on the magnetic drain plug, no bits on the filter on the end of the oil pick up in the resevoir.