That was me.......
I had a rear box fitted the quality is good as well is the service but i went for the mid sport option but its not much louder then stock i also noticed recently that it sounds a bit raspy until its warmed up and may be blowing a bit. iam a little disappointed and if i lived closer i would have gone back i might still yet and get them to replace it.As there come with a life time guaranty
I had a v6 x-type jag and had rear boxes fitted by them and it sounded great really pleased so a bit miffed.
In my opinion save up and buy an off the shelf one from a well known company i just think there dont suit a straight six engine set up.