Heya. Got your PM, thought I would reply here to everyone can see it.
First, in my experience '06's *DO* have harder clear than '03-'05, however I wouldn't call it scratch resistant. It is still significantly softer than most American/German paint. It's just not stupid soft like the 03-05's.
So, if you have an '03-'05 the key is *many moderate steps* as opposed to one hard compounding then finishing like you would normally do. For example, using Menzerna IP/orange x2 + FPII/white x2 will likely achieve better results than PG/yellow x1 then whatever for two reasons. One, Infiniti paint is finicky with letting go of deeper marring. It seems to like slow moderate passes rather than tougher polishes. More importantly, if you do a compound like ssr3/pg you will create enough haze with a PC that it will be a *total pain in the butt* to remove. Better to use a moderate polish a few times and create a small amount of micromarring that will come out reltatively easily.
A second tip is when finishing, if you find you have some micromarring/haze that will not go away try a super light combo, like FPII/grey @ speed 2 SLOW passes no pressure; oddly unlike harder paints this seems to take out the micro marring and finish smooth.
With a rotary things are different. Infiniti's are much easier to deal with. With a PC it's a bit tough because its hard to finish down well. I've not used the XMT series, so I don't know how it'll work; but I would just start light and move up until something starts to work, then do as many passes with that as required.
Hope this helps.