I took delivery of a 2015 ML250 on Saturday. The vehicle has the lighting package. Salesman told me to drive it with the light switch turned all the way to the right for the lights to work properly. The owner's manual states to drive it with the switch on auto and to push multi-stalk forward to activate automatic high beams. Can anyone tell me which method is proper?

 

This is correct.

 

What the salesman was trying to express to you - with the Lighting Package - in auto mode the high beams will only come on at speeds above 55/60 mph AND in the absence of any oncoming light (incl streetlights). At lower speeds high beams will NOT come on in Auto model.

In Manual model - you have the choice of scaling "up" to High beams at any speed.