Anyone have rust on their Mac LT headers?

[Roush21]

Hi a friend of mine put some AWESOME Mac Longtube headers on his 95 Trans am and I was in the market for getting them for my 98 cobra. Hes had them on for a few months now and is now starting to get little bits of rust pop up...anyone have this problem w/ their? They are the coated headers and he said they were expensive like $700 for his trans am but theyre like $329 for my cobra and also i dont drive my car in the rain or that much at all really. SO if anyone has anything on this please let me know. thanx