Have had this happen a few times, all you need to do is take your grill off and unclip the little spring on the bonnet catch, then head out to a scrappy and grab another spring from a mk1 or mk2 bonnet catch, then hook it on where the previous one was, 5 min job and no tools required, as long as you're talking about the spring i'm talking about!!! Easy way to tell is if you look into the bonnet catch is it a clear hole through or is there the bit of metal which acts as the catch sticking into the hole?