Is the smell similar to a water vapor smell? Do you smell this all of the time or just once in awhile?
What you might be smelling is the completion of the Regen cycle. I also use to smell the Regen finishing up on my 08 Ram but the truck lost the Blue-Tec emissions somewhere. Now my wife's Jetta has the same orders when regening.
11 Jetta TDI DSG Auto with Nava system, -Wife's
08 2500HD Mega Cab SLT, 6.7L CTD 68RFE,Optix Gauges Pyro,Boost,Trans Temp A Piller mount, Mag-Hytec Trans Pan, Front & Rear Diff Cover, Smarty, MBRP 5" Exhaust, Silver, Westin Side Steps, Line-X Spray in Bed Liner over the rails, Bed Cover, Prodigy BC, 15K Reese hitch and pulling a 11K 5er-My ride