Does the Spec-S come with a bung?
Or is it an option?

 

No it doesn't.

You can buy the bungs from Blitz (at least you used to be able to).

If you get one you will have to drill a hole in the tail pipe to be able to fit it though. I got a bung for mine but I've never used it and have never got around to drilling the hole.

 

Here is the bung for sale direct from Blitz.

http://www.blitz-uk.co.uk/ProductItem-115.aspx

 

Thanks very much Sir
See how it sounds and go from there.