I actually recently took the included USB-c cable from the wife's Model 3, and installed it in the Model S cradle. It fits perfectly on the phone side. It's not right angle on the supply -side USB-A, but if you don't mind that it sticks straight out next to the 12v outlet, it works fine.
BTW, I have a new, sealed Model S/X charging kit (iPhone and micro-usb) to sell; bought from Tesla before noticing the new car had one included sitting in the frunk....