MB AdBlue system is a time bomb. Just failed on our 2013 GL350 at 56,000 miles. $5400 repair estimate originally (heater, sensors, etc). We ended up selling the car to the dealer and buying a Ford. 2nd Mercedes and dad to leave the brand but won't be back.

Buyer's beware. From what'll I have now read and experienced it isn't a matter of if but rather when you will have costly issues with Adblue system. Would still be a happy MB owner if they had done the right thing and covered cost of repairs.