@ashley g- I am wondering the same as I have a reservation to hike soon and I am not sure if I will be able to make it to the upper TH or will need a ride... and will be able to get a ride with COVID guidelines...
I was up there last Sunday 5/17 and although there wasn't any Subarus up there, we had a Jeep Compass 4x4 with really good tires and we were able to make it up to the upper trailhead just fine. There are some steep slippery parts of the road a little past 1.5 miles from the HQ that a Subaru with bad tires might not be able to go up. But as far as clearance goes a Subaru would have no problem.
