hi i bought my astra 2.0i bertone convertable last year, i was given the recipt for the 3 year guarntee for the exhaust that was fitted in sep 2007 so i belive its valid till sep 2010, now it has a few holes in it has anyone ever took one back for this? and what response did you get, remember i did not have it fitted the person before me did, so will it still be covered? thanks