It may be worse than it was a few years ago, but I drove my outback most of the way up the road. Broke part of the plastic off the bottom when I slid off a log "bridge" over a creek. I decided to park it. There was a Dodge Caravan minivan at the trailhead, so I decided I was a wimp.
That said, I would not try to drive back there again. Listen to M5 and just walk. Driving was so slow that it didn't save me much time and wasn't worth the wear&tear on the car.
I walked that road in early August: I would think that you'd need a true high-clearance vehicle, but the worst of the ruts were very near the bottom, so you could scout it out on foot and make a decision.
The walk is not bad at all, but we were bushwhacking up the S. Fork of Black Creek and had a very long day ahead of us, so the head start of driving the road would have been handy.