i have a theory of why the ML & GL models don't have an off-gas build-up like the E...more cabin volume. My ML didn't smell like a plastic factory, unlike the W212. I test drove a GL450 a few months ago, and it didn't have the plastic smell of the W212 either. The ML and GL do not have the same plastics as the W212.
MB was offering a fantastic deal on GL's, however I decided to end my relationship with MB, thus the 550.