Fine metal flakes in exhaust?? 2011MS3

[Pacman]

I walked to my car yesterday and noticed this in my exhaust. (Cpe custom exhaust, I believe cat back) They blew away on the drive home, and I don't see any new flakes. Is this something to worry about?
Car is a 2011 mazdaspeed3

http://img.tapatalk.com/d/14/10/09/epyqydys.jpg

[Hyperion]

Something, either your cats, resonators, or muffler may be on their way out.
However, if this is a one time occurrence, it may just be some gasket sealer that finally broke off.

[Pacman]

Never noticed it before. Car has 55k on it. Could it take that long for a gasket sealer to break off?

[n00bMeiSter]

how long ago did you install the cpe exhaust?

[Pacman]

I bought it with the exhaust. Had 24k kms on the car when I got it Oct 2012, and car was purchased by original owner in Dec 2011.