Well my 3.2 is now 3 1/2 years old done 26k and it's telling me I need it's 4th service!! Vx tell me it will have new plugs put in and as I've seen on previous threads it seems a bit of a job to do so I thought I'd put the best plugs in I can. Can anyone tell me what to use, where's the best place to get them and how long will they last please?