Nice purchase! I'd have one by now if my GF hadn't decided that a New Zealand holiday was in my best interests :P
Regarding rattles, I've aways found that doing a careful job of identifying each one and either tightening the bolts or bunging some foam in between them helps no end. Then engine speed doesn't really matter.
Lining the tool boxes and compartments with cheap, grey, outdoor carpet could really help quieten the load. I've done this with a number of old ammo boxes that I use for camping gear and also used the same stuff in my dad's S3 ute. Things like semi-ridgid metal handles on cargo boxes can be silenced with a bit of velcro.

