CLS63 exhaust tip on CLS500
Also best exhaust would really depend on what you like and how deep your pockets are. I and many others did a resonator delete and sounds amazing. I ran straight pipes instead of x pipe as its a little more aggressive and find it to be wicked nice with my lorinser exhaust.
I personally would start off with resonator delete and go from there. You will love it.. And it's only $150 area depending on where you go





