I bought some stainless steel tubes and elbow and got them TIG welded by a professional welder.
I turned the clamp around and re-shaped it to have the muffler hanging, I think it is much better than my first idea.
Here are the pictures of the exhaust mounted on the Roadster. I think it looks pretty cool.
2013-12-04_14-38-14 par
Voucht71, sur Flickr
2013-12-04_14-38-43 par
Voucht71, sur Flickr
2013-12-04_14-44-27 par
Voucht71, sur Flickr
I might add another lower mounting point on the lower part of the muffler, I asked the welder to weld a bracket on the clamp for that, which he did.
Now, the surprise will be at the MOT (when the car is finished). Will the exhaust pass the noise and emissions test? Anyway, for now, I started the engine with the exhaust line fitted, and here is how it sounds and look when running:
http://www.youtube.com/watch?v=Y2VpdHpMDG0
One more time, Kev was right, I will need a deflector at the end of the muffler to protect the rear arch... I have my idea about that to make it look not too ugly...
To be continued...