Got in this morning, started her up and straight away heard another mysterious ticking noise. Oh no, what could that be, I thought, in a state of half panic, Turned the radio off and gave the throttle a blip to have a better listen. My daughter, sitting next to me, gave a sigh, rolled her eyes and, looking out of the window, said "it's that!", pointing to the sat nav lead vibrating against the low/high knob. The cold had made the lead hard.