Hello Peter, many thanks for your reply and your personal welcome to the Jaguar Owner Club. The font i used may have hidden the fact that my car is a Jaguar XF and it is fitted with a battery monitoring system (BMS) and the connection is on the negative terminal of the battery and I am concerned that this could be detrimental to the system if I connect directly to the neg terminal rather than the frame. I am probably being over caseous but I fear damaging electronic components which abound on today's cars.