I re-did my (black) daily driver with a Graphene coating last May and it's doing very well, quite impressive w little maint on my part.
Is it because it has 'graphene' in it? I have no idea, nor do i really care much as long as it keeps working well. Impressive enough that I'm gonna throw it on a new work van this winter as it seems to do very well in low maintenance situations. Only been 6 months so no real idea if it's got the legs to be a good one but its come outta the gate very, very strongly.
Despite all the info on how hard graphene is, I thought I read somewhere that its resistance to marring had to do more with deflecting the angle of impact or slickness or something other than 'harder than XXX' and its resistance to permanent spotting/staining was partially do to somehow resisting heat in the panel. Again, the science is beyond me (or not really of any interest) and as long as it keeps working well, that's good enough, whatever the reason.