Cool, thanks for the update! How did it go on the highway? Mileage?
Do you have a weblink to the 5mm spacers you bought but didn't use?
The trip on the interstate went very well. It was a very windy day, winds gusting from 15 to 25MPH out of the southwest and I was headed south to southeast. There was some buffeting from the wind that moved the car slightly, but not bad. I drove the car home from Tesla on the interstate with the stock wheels and tires in similar conditions and this trip was no worst. I used auto steer and just kept some pressure on the wheel in the direction of the wind. On the trip back, as luck would have it, the wind turned around and I was heading into it at an angle again. My total trip was 208.9 miles,with about 2/3 interstate driving at 70MPH. I had 74 miles of range showing at the end. I have a 100D and charged it fully the night before. I started with a indicated range of 304 miles, which surprised me as the car is rated at 295.
You also asked about the spacers. Here is the link:
5x120 72.5 5mm Aluminum Wheel Spacers Adapter Pair for BMW | eBay
As you can see, they are for a BMW, but fit fine. I did not drive with them on the car, but mounted one on the car with just a bare 19" wheel to check fit and had no problems with clearance. I had plenty of threads for the lug-nuts as well. I plan on trying at least 2 of them on the car now that I drove without them on the highway. I want to see if affects the balance and the feel of the steering.
Again, this wheel and tire set up works for me with my 5 passenger X. I do not have a hitch and do not plan to overload the car.