I changed my oil this afternoon and when I pulled the drain plug on the rear sump there were what appeared to be metal shavings stuck to the tip of it. I first freaked out and thought the worse then I cleaned the oil off of the shavings and took a closer look. I noticed they looked like the circular shaving left over after you tap a hole for a bolt in metal. Ever since I bought my GT the threads on that drain plug have been a bit screwy. You could screw it in with your fingers about half way and then you needed a wrench for a few turns then it would turn with your fingers till snug. I guess when I put the new magnetic drain plugs in last oil change the bad threads in the pan broke loose. Luckily they stuck to the tip of the new magnetic plug instead of flowing through the engine! The little pieces of thread may not have caused any damage, but I am glad to know that because of my magnetic plugs they never even got a chance to try!