I was just reveling about the x-drive system yesterday as I parked my X5 with winter tires in front of a house on a steep slope facing up. As I walked back to my vehicle another car had parked behind me (think San Francisco with lots of snow). I eased off the electronic park brake, put it in to drive and had no problem driving away - even with a full coating of loose snow on the ground. It felt like I was defying physics.
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17 Tesla Model X 90D (I've been converted!)
PAST: 14 Tesla Model S P85D, 16 X1, 13 X5 M-sport, 04 M3 Cab, 08 E92 M3, 08 535xiT, 07 X5 4.8i, 06 E90 325i, 87 E30 325i, 85 E30 318i