I replaced the plugs in my Neon and stabbed in some new plugs without looking up the Country Of Origin because it was an 'American Brand'. I torqued them to spec (with a calibrated torque wrench), and went on with life. A couple weeks later the wife was driving it and it blew a plug out of the hole. The helicoil kit to fix the screwed up threads was $200 by itself, but I had to because it had chewed the hole up while the plug rattled around. I hate doing that because it's a four-valve aluminum head and removing the material for the thread inserts gets REALLY close to the press-in valve seats.
I went back and looked at the box, and sure enough: Made in China.
I looked at the plugs that came out, including the one that had blown out, and NONE of the gaskets were compressed or deformed. I threaded them into a junk head I had laying around, thinking maybe I'd just forgotten to torque them down. I torqued them to the spec on the box (which jived with the manual), and sure enough, the gaskets do not deform like they're supposed to
I'll NEVER use Chinese anythings unless there just is not another option.