Ill be doing a oil change shortly and have seen the large magnets that go in the front of the oil filter. There fairly cheap are they worth using. Ive already picked up a magnetic plug.

Unless it somehow causes interference with some sensors (which I've never heard of happening), I would say that this is certainly worth a try. You should cut open your filter before you put it on, then again after to see if you see sny difference.

I've never used one of really known of anyone that's used those.

Ditto.

It would seem that if bits of magnet sensitive metal are floating in the oil, that would be a more than a major problem on a C5, as the pistons and bores (main wearing parts) are aluminum. I have seen the magnetic plugs used effectively on manual transmissions, where there is no filtering, and you may pick up some "dust" during break in. And they were used extensively back in the days of bypass filters - long gone for autos, thankfully.

The regular engine filter will catch anything untoward, IMO. Personally I have never found any debris in the old oil - and I do look!

One thing I personally do. The synthetic lubes may be good for a zillion miles, but filters are generally reckoned not to last as long as the oil. At 50% max "used" on the display, it's oil and filter change time for me.

1998 55k+ miles, uses no oil between changes - as it should be.

I think I could see benifit in a magnetic plug.

Thanks for the great info as always