This signum came in with the back boxes blowing on it. The replacements were expensive to say the least and the owners fancied something a little sportier so we decided to build him the rear section in mild steel. the car comes with a large centre box and 2 massive back boxes. To our surprise with the rear boxes removed the car sounded a bit more aggressive but the noise was hardly any louder. We had expected to need to replace the rear boxes to keep the volume sensible but Vauxhall had obviously been pretty cautious with the number of boxes fitted. With some simple pipework and a couple of nice tips the job was cheap and sounded great.