Ok this is pretty nuts. So I bought a 20 pack of non-oem, Toyota/Lexus spec drain plug washers a while back. I did an oil change on my new to me, IS500 several days ago and used one. Torqued the bolt to 30ft lbs and everything seemed fine. My magnetic drain plug arrived yesterday so I wanted to put it on. I decided I would do a quick swap of the plug and just add a little bit of oil afterward. When I went to remove the drain plug, it was so loose I could unscrew it with my finger!!! This is after less than a week since I changed the oil. Thank goodness I am impatient and wanted to put the magnetic drain plug on! I thought that maybe I just had a bad washer but I started Googling and saw that many others have experienced this.

Here is a picture of two oil drain plug washers. On the left is the Amazon washer, after maybe 250 miles? 500 max. You can see it has deteriorated and almost had the material squeeze out of the sides. No wonder if loosened up. On the right is an OEM washer after 5,000 miles.