Not sure which side of the line I am on. I have managed the 12 inches of snow and ice here in Indianapolis last couple of days driving my CLS550 back and forth to work with the 18" AMG wheels with Conti Sport 2 tires. I have been more than impressed with how well the CLS has handled the conditions.
Actually the hardest part has been getting out of the parking lot at work come the end of the day. The adjustable ride height Airmatic has been a saving grace as most driveway entrances have turned into mountains of plowed snow and slush. The AMG front spoiler is still in place.
I learned a lot about the ESP the last few days. With all the electronics on, the car will not move or spin a wheel regardless of throttle angle if there is no traction. I often have to switch the ESP off to get some forward momentium with a little wheel spin and then switch it back on once rolling. It works very well for keeping the car going straight when I see other cars sliding around. This car causes a lot of envious onlookers in the dry, so you can imagine the looks from AWD and 4x4 drivers in these conditions.
I would have to say the rear differential could be a bit tighter. Uncontrolled one wheel spin with the ESP off has often made things more difficult than if both rear wheels would receive some varied amount of torque. I should have expected as much because in dyno mode, both my CLS550 and a friends CLS63 smoke the inside tire rather than the rear stepping out.
My only "lesson learned the hard way" was to clean all the snow and ice out of the tray housing the passenger side wiper linkage. I scraped the windshield and made sure the blades weren't frozen to the glass but the tray was full so the wiper linkage couldn't articulate. As soon as I turned on wipers, only the driver side moved. A 5 minute stop by the dealer on the way home last night solved the problem painlessly. (Other than almost getting stuck in their parking lot!) Rather than scramble the linkage as would happen in the past, there is provision for a linkage joint to pop apart. Those clever Germans!
I wish I would have taken some pictures with the car at max ride height and fenderwell packed with snow and ice. It would have been a stark contrast to the usual beauty shots posted here.
Sorry to those of you who might think it shameful to exposing a CLS to such conditions, but a great car is a great car and it should be enjoyed.