did anyone see watchdog tonight! about the zafira b 05 to 07 models and the astra that looks like it is it the astra h . when the head lights are on the horn dont work on some cars just thought i would put this on as its not something you think of till it dont work and you realy need it . they said one house hold has four astras and none of them work with the lights on so there is a fair few out there that have the problem. could fail the mot if the lights are on when the horn is tested .