Hello Oliver. I don't think you will find any of the answers you seek in this forum. It has been set up for the benefit of GLC owners, an SUV that only came into existence in 2015. I think you will be better served by asking your question here:
A forum community dedicated to Mercedes Benz GLC owners and enthusiasts. Come join the discussion about performance, reviews, troubleshooting, maintenance, modifications, classifieds, and more!