You can clean it up but I don't think the stock exhaust is stainless so you will only get it marginally good.

It does look like someone's either cut off the grill that covers it, or folded it up out of the way.

There are quite a few options for shiny stainless aftermarket exhausts for the N/A.

If you don't like the idea of having an exhaust that's bigger than your engine then you can get a blueflame or mongoose exhaust

- these still have the large central silencer with twin exits.

Or if you like having massive cans you can get a japspeed exhaust but they are LOUD.

I don't remember off the top of my head whether there is a motoria exhaust for the N/A as well.

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