Found this reply in a thread related to cleaning the exhaust tips. Found out that the tips are stainless, not chrome. Seems that they are infact painted black for the SRT6 but looks like carbon built up, I too used the SOS Pads and when cleaning off the "paint" it too doesn't appear to be paint but rather black dirt coming off. I much rather have the clean shiny look than the black anyways so I may just continue using the SOS pad to clean them up and maybe some turtle cleaning polish..

Spudracer used the SOS pads to get them clean and has an SRT6, quoted his post check it out:

crossfireforum.org/forum/detail-shop/48747-cleaning-exhaust-tips-2.html#post580717 (copy and paste into browser, if you click it takes you to an unavailable page.)

Read the rest of the replies in that thread.