Yes, as the others have said here tires are the key. I have a set of 4 snows on a spare set of wheels and have no problems at all with my E300 and don't cart around any sand. I think also there are some all season tires which are better than others in the snow so maybe your tires are just not really good in the snow and you wouldn't have trouble with a good set of all seasons. I have found really dramatic differences in how tires make a car handle in the snow. I had a Cadillac Caterra which was TERRIBLE in the snow on the Goodyear all seasons...but as soon as I put a set of Michelin snows on the back it was like a different car altogether. My wifes AWD C240 has Pirelli all seasons on it and handles fine without any need for snows. I think those pirellis are good all season tires but I still went for snows on my RWD E300.

Also, try the "W" mode in the transmission instead of the "S" mode. This starts you off in second gear and adjusts the shifts to keep the rear wheels from spinning. I find it helpful too.

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Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz