After completing my oil change and sample collection for annual UOA, I pulled the dipstick and found several areas of "active" rust near the top of the dipstick. I noticed a few small (1/8") spots of surface rust on the last oil change and wiped them clean with an oily rag. This time the rust has "blossomed" into several scaled areas 1/2" long. I will replace the dipstick asap - maybe under warranty. Could this rust skew the UOA somehow? Thanks for any opinions.