I know, I can't seem to pinpoint the evidence behind it, the CEL disappeared after months of driving with it lit up. Sounds subjective but the additive really seemed to made the engine run smoother too. Maybe proof of how substandard most diesel fuels are in the US? I used the Kleen additive before but it only clogged the fuel filter (at least that's what the mechanic told me)

I feel like forwarding this thread to that BMW SA/ mechanic who insists to replace the SCR cat.

Still crossing my finger hoping the CEL stays clear.

This is not completely correct, as air suspension was an option without third row seating. ALL 3rd row has air suspension, but not all air suspension has 3rd row.

Non 3rd row air suspension is a pretty rare feature. It's more common to have deleted 3rd row than to have a build like that! They do exist though.

I put Airlift helper bags in my rear springs, since I tow a low and don't have factory air in the rear. They helped a ton, and it handles the trailer WAY better.

AirLift Install?
 

Do you happen to have any pictures of your Airlift air spring install?