I dont think the Janspeed back box would fit my system as the length of my exsisting backbox is huge. I popped down to Mike stokes last night and judging by the cooper S system he had in the window the standard is very good,the welds were a work of art it just looked spot on and bearing inmind it had duplex backbox setup £350 was very reasonable..Not sure what design tailpipe to go for,my current system is 3" so maybe 3.5" but i dont want stupid loud as my 3 yr old son wouldnt share my enthusiasum for it,id like it to pop and crackle on over run but i suspect that would mean removing the inner silencer box which i imagine would get abit loud? perhaps getting a tailpipe design which has the removeable end plate would quieten it down?
Your thoughts/experience on that kind of set up please