[boraz]

First question is how do you know how much DEF you actually have? The display tells me "DEF OK" but no actual quantity. I want to make sure that it is at least filled on delivery.

reads OK until 35% left then counts down numerically...at like ~10% or something you start getting warnings....at 35% it will accept the 2.5 gallon jug of DEF

FirHow do you know how full the particulate filter is, and when a regen is about to happen.

there are no warnings on the car for any of this, youll need an aftermarket scantool for this, scangauge2 is popular on this site, i just use iphone app and BT/WIFI obd2 dongle