Drove into American Basin from Silverton on July 27. The Cinnamon Pass road is in good shape from Silverton to American Basin, with the normal small rock outcroppings being easily navigated through once you see the tracks. The creek crossing on the road to the TH is easily crossed - the north bank isn‘t as steep as it looks. All handled very well in my Patriot.
There was a Ford Focus parked along the TH access road before the creek crossing that came up the road from Lake City. Assuming one drives the road with care, a car with at least the clearance and capability of a Focus should be able to get up from Lake City.