I had the rear logo get some sort of running water spot as well in it, it started small and started to grow, the chevy dealer replaced it when I had to have a key fob replaced as well (the solder inside came loose) luckily both were under warranty. Took about 45 minutes and both problems were solved.

 

yep, probably get an overlay or paint.
https://www.chevyhhr.net/gallery/showimage.php?i=13372

 

My Half Hot Rod was in to have the BCM replaced, when i showed them my rear bowtie that looked like it was cracked or peeling or something.... anyway they said oh no problem we have seen these like this before. we will fix it... they replaced it.

 

my rear bowtie is again getting waterspots under it again, and these are only 4 months old. Going to have to go back and replace them again, luckily still under warranty