Diesel juice??

[Ronin]

All I did was go to O'Reillys and buy a 2.5 gallon container of AdBlue. It had a nozzle about 5" long, which was thin enough to use to fill both tanks. There was some spillage, but it's easy to clean up (remember not to leave this stuff on your paint...it will chew right through it, given time). To avoid spillage, take your time, and make sure to poke an air hole in the back of the container.

[Sylvan Lake V35]

I know this old but I found it useful, I am just off warranty and I thought I had to buy the urea from BMW good to know its standardized.