My Thunderheader was wrapped... it turned into a rust magnet. The wrap trapped moisture, held it against the pipes and caused some pretty serious rust and pitting.

I would also recommend against doing this... unless you want to try out new pipes every few years.

 

Mine aren't wrapped and they turned into a rusty mess within 6mos. I'm not sure of the process they use to chrome their exhaust but it stinks. That's why I painted the headers flat black, to cover up the nastiness.