I have the Flowmaster dual exhaust system with the transverse flow muffler on my Camaro. I've seen other transverse flow muffler systems as well. However, THIS is the first time I've seen this type of exhaust system. I wonder how it sounds. The mufflers look really small.

 

I haven't seen those before either. Can't say that anymore I guess.
Given the small size of the muffler, I'd have to imagine that it would be loud. Not that that's a bad thing!