Went for a drive after changing spark plugs yesterday, only 25k miles but others have said they noticed a difference, so thought why the hell not, definitely starts up better and a little smoother at low speed as others have noticed, went with the HKS M40HL plugs
bought from fensport, who initially sent the wrong plugs by accident, but they sent the replacements the day after I emailed by next day delivery and refunded the initial postage I paid, which was more than the return postage I paid for wrong ones