Looking at the rear main muffler on my XKR I wonder how the pipes are inside. When you open up the baffles how does the exhaust flow inside the muffler. The baffled pipes are not direct flow open exhaust so what does the inside of the muffler look like.

 

Here is the schematic from the X150 Workshop Manual.

You can purchase the Workshop Manual over the Internet.

 

That may only be diagrammatic, of course - it's demonstrating the difference between open & closed active exhaust valves, not necessarily the detail of how gas flows through the muffler.

 

The pipes typically have openings that allow the exhaust gasses to 'expand' into the larger area that may or may not contain baffles, thus is the level of exhaust noise controlled.