looks like this Fall, I will be driving a Benz or a BMW. The ML series will be getting a 3.0L diesel here in the US. The X5 is also going to be diesel. Audi?

Doesn't seem to care about the US, and really, why should they? No profit here. But as far as my needs, I will be selling my S6 this Fall and buying. The upcoming NY Auto Show will be a good reference. The Audi announcement at Beijing will probably be the deciding factor.<ul><li><a href="http://www.motorauthority.com/cars/mercedes-benz/mercedes-benz-prepping-three-new-diesels-for-us/">http://www.motorauthority.com/cars/mercedes-benz/mercedes-benz-prepping-three-new-diesels-for-us/</a</li></ul>

The stuff is pretty corrosive and can only be stored by licence AFAIK. It is not recommended for manual dispensing. It is not sold over the counter.
The Q7 tank holds 6.2 Gallons (US) topped up at service.