Here is a cheap back box and what the seller sent me,

Dear lazylunatic,
.. here?s how it works.. (quite easy to fit)..
we supply the parts to fit these and they come with the CORRECT INLET DIAMETER FOR YOUR CAR so just need your make, model, year and engine size when making payment.. these fit by cutting through your exhaust pipe immediately behind the old back box, then removing the old back box and installing the new one by bending THE HANGERS THAT COME WITH THE NEW BACK BOX and connecting up either by welding or by using flexible steel exhaust tube and clamps which we can supply at additional cost as a FITTING KIT which is of the correct diameters and size for your particular car. cheers
Not worried about the piping, just use flexi stuff and loads of exhaust sealer/grease stuff. Securing it in place is the hard bit... any ideas.
Cheers all
LL
