Searched like crazy through the site to see if this was discussed, but can't find it. Re: Model S - 19" wheels - I see that in the online Tesla store they sell Z-Chains for $89.00. Model S Snow Chain Tesla Motors Has anyone bought these, used these and have feedback? I wonder which version of the Z-Chains they are - they make a Z, Super Z, Super Z6 and Super Z8 - and I wonder which ones work best on the Model S. I would use them 3-4 times a year driving for less than 10 miles a time. Amazon has them cheaper, and with a prime membership, free shipping - just want to make sure I order the best type for the Model S. Security Chain Company Super Z6, SZ143, Cable Chain for Passenger Cars, Pickups SUVs - Set of 2 : Amazon.com : Automotive Any thoughts experiences with these chains?