Bloody hell - I got the M6 back today with the exhausts fitted and pulley kit - it sounds absolutely AMAZING!
It is exactly what I wanted and is still quiet / ok on the motorway which is what I wanted.
I am very glad that I didnt go for the race option on the Eisenmman - I think that would have been a step too far for me.
The X pipes definitely gives it a little more noise and purpose.
Anyway thank you again for those parts, the help and advice.