I had the Proxies on my Cayenne and they were good. I could not find either the DWS or the Proxies in 20s for my x5, so I picked up a set of non-run flat Latitudes and they are awesome. One of the best tires I ever drove in the rain. They are a bit more expensive, but IMO worth it.

FYI, I have a set of 18s with Latitude Alpins for the winter. I did not use them too much on x5, but the same set of tires were on my Cayenne and excellent in ice and snow.

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11 E70 x35D
07 E92 335i*
05 E83 X3 3.0*
02 E39 540i*
92 E36 325i*
* Retired/Sold