Personally, I think the best way to go is the FilterMag SS250 Oil Filter Magnet versus a small surface area, magnetized drain plug. Also, rather then fooling with a drain plug at all, consider replacing your stock drain plug with a Fumoto valve..the best.... if you want to attach a hose to the Fumoto do order a Fumoto that has a
nipple on it for hose attachment. (not all Fumoto's have a nipple)
Futmoto's part# will have an "N" in it indicating "nipple" if it has a nipple. The Fumoto comes with a fiber gasket. Use the included gasket alone on the install.
For the '09 - '11 370Z use the F103N Fumoto valve.
Best place to buy price wise is from an eBAY vendor. They do not leak and are very well made. A terrific adjunct. 8-) I've used them on numerous vehicles over the last few years.