My first replacement battery died today and as there have been many posts in the past about successfully fitting the larger 70AH battery from the Diesel to the Petrol I decided to go that route. I checked the parts and the battery tray, clamps etc have the same part numbers for both the Petrol and Diesel. One of the recommended batteries for the Diesel is the Yuasa 031 which has dimensions 258MM Long 173mm Wide 225mm high Previous posts have mentioned the Halfords HB072 which has very similar dimensions would fit. This was on offer for £93 I managed to source a Bosch S4 069 with 4 years warranty from Eurocarparts for £68 (special online SALE reserve at store jobby) http://www.eurocarparts.com/ecp/p/accessories-car-batteries/car-batteries/other-batteries/other-car-batteries/?444770697&0&cc5_1026 (The battery is marked Bosch S4 027 but Eurocarparts refer to it as a 069?) Fitted no problems, you move the metal clamp corners out one hole each and place the holding rods in holes at the side of the battery holder base. The was also no problems with moving any of the wiring. However the length of the Bosch at 260mm just fitted centrally, as there is a thick wiring loom on the passenger side that would get in the way if a longer battery was fitted. A Couple of pictures attached if anyone else wants to go the same route this winter. Its really simple and its not worth fitting a new toy 45AH battery.