If it's engine oil that's leaking - as evidenced by the low oil level - you have two separate issues as engine oil level won't cause a steering noise. (mechanics.stackexchange.com)
Mercedes - Benz AG engineers apparently have enough confidence in their onboard engine - oil quality monitoring system — dubbed FSS, for Flexible Service System — that they have decided it is superfluous to include the time - honored dipstick to check engine oil level. (wardsauto.com)
Multifunction displays in speedometer face - inc: trip computer engine oil level check digital speedometer reminder / malfunction messages driver - programmable settings navigation system route guidance exterior temp gauge audio status engine coolant temp (chicagomotorcars.com)