In this case unfortunately yes, the parts feel great honestly and I'm not even sure they would affect the warranty, I was told they wouldn't, but being that I just paid 18 grand for the car and I still owe 2 thirds of it, ive decided not to take the chance, a few hundred to get a youthful urge out I consider not that bad of a price, being that I've paid much worse in the past. Anyway they really are awesome parts, just not for me, I'll wait till I can afford the 2013 s60 t6
Entire warranties cannot be voided due to the installation of an aftermarket part.
Warranty coverage on individual parts can be denied if it can be proven that the aftermarket part caused the failure. With that in mind, a downpipe won't really stress any engine components, or put any warranties in danger.