I'm still waiting on my invitation to configure (assuming it's coming in the next month or so). However, I've begun doing some "housekeeping" items to prep. Among them, winter tires. I recently picked up a set of 18" wheels to use for winter tires and plan on picking a set of winter tires that I've had my eye on, as the local stores begin to mark down winter tires, as we're heading towards the end of winter shortly. Which brings me to my question. Given that I'm purchasing these and having them mounted before they're on the car, I assume the 3 uses TPMS and that I'd have to have the sensor ready to go when I have the winter tires installed. Has anyone purchased a TPMS sensor/assembly yet? Did you go through Tesla to get it? If so, what do they charge and are there any miscellaneous additional items I would also need (caps, nuts, etc)? Alternately, has anyone sourced these outside of Tesla directly? Thanks!