2013 E Class 220d suddenly started jolting whenever lifting foot off brake when vehicle stationary and in Eco mode (stop / start to save gas). Significant jolt occurs when stopped engine restarts. Feels like letting clutch straight out in manual mode with engine at say 800 rpm Dealer suggests this is unknown (to MB) problem and suggests software updates be applied to see if it fixes the problem. Technician road tested and collected stats confirming problem exists but Seems there is no assurance the problem will be resolved as there's no indication that software update was issued for such purpose. Car had been previously "B" serviced some 8 weeks prior and no software updates were applied at the time. Concerned I may be paying for Eco mode R & D which MB should have zero defects after 5 years! Any suggestions as I feel I and my wallet are in uncharted waters!