So I picked up my new 850 on Friday and asked about a set of spare plugs. Parts guy couldn't find any info on them. Did a little more research and "supposedly" they are $40 each and yet can't find any info on them. The owners manual actually states that the dealer should change them. Are they indexed? So my first question is, do these ever need to be changed? Has anyone with a new Doo picked up spare plugs? Really curious about this one as I'd hate to be in the back country and not have a spare set.