When I got my ST205 it came with a 3" mandrel bent exhaust made locally. Unfortunately it had two poxy Cobi bullet resonators in the middle and a tiny oval muffler at the rear.
Can you say drone?
Anyway the plan is replace one (or both) resonators with a small oval muffler in the factory location and get a large rear muffler, something like the photo here:

Is this style of muffler available locally without special order from Japan?