I too had my TD's black end caps turn purple on my 08 SERK. My selling dealer swapped the black ends for chrome in May. The chrome ends are now peeling right where it reads Rhinehart (fitting

) Here is the email response I received in regards to an inquiry I had made about a remedy. It is NOT just the black ends they are having trouble with.
Dear Howard,
To obtain warranty service, you must provide us, via e-mail or fax, a copy of your dated receipt as proof of the purchase. Make sure your name, shipping address and daytime phone number are included. We will also need to get from you a credit card number to insure that you will be returning the defective parts for assessment. You will not be billed unless we do not receive the defective parts back or if upon return the inspectors feel that the parts are not defective. To expedite your claim, please include a short note including bike make, model and year; exhaust type & part number (if available) and also the nature of the problem.
You should know that BUB Enterprises, Inc. has a standard ninety day, from the date of purchase, warranty on all merchandise. We extend this warranty against defects in material and workmanship for a period of one year from the date of purchase. Please contact our BUB Sales department at BUB@bub.com for prices on replacement parts for systems over a year old.
We will process your warranty claim once we establish your account. For the past year and a half, our Rinehart end caps have been processed with a black Teflon finish that we are confident, at this time, will withstand the heat of the engine and hold the true Rinehart black color. Chrome end caps are considered an accessory and not offered as warranty replacements. If you purchased the chrome end caps and have a copy of the receipt, we can offer warranty replacements for them as well.
Thank you,
Linnea Johnston
Warranty Manager
BUB Enterprises, Inc.
Linnea@bub.com
Phone: 1-877-282-7473 x220
Fax: 530-477-7485
Sorry, pic taken on phone. Peeling is at the "R"