The side vents are also similar. IMHO: In both the C6 and Viper, I think it's the most inconsistently styled feature on the cars: Smooth curved lines everywhere except the vents. From the C6's side profile, it really looks like an afterthought or at least something that was done solely to differentiate it from the C5.
However, I think it looks better than the C5, overall... The lumpiness is gone.