Wobble67, today I was exactly in the same position as you were then, and it seemed my only option (having only ONE key fob) was to trawl through the (currently full) kitchen bin! ...but, I'm glad I did - it was horrible, but unbelievably, I found it! And when I re-inserted it back into the key the immobiliser got out of the way and the car started! It seems then that this "PATS" can easily fall out when the key fob is opened - bad design in my view!