Also pay attention to weather. If it’s rains, which it shouldn’t to much anymore you could be stuck out there. And now that I think about it right as you come into the parking lot there’s a good size dip you most likely won’t make it over. Just park outside and hike if you can’t.
There's plenty of low clearance vehicles in the parking lot on any given day, often a prius or two.
Van Dusen is less rugged than Polique.
Van Dusen is rockier towards the tee junction - these are small rocks, sub-surface, or on the surface - small hatchback suspension systems are not designed for this kind of punishment - so while most cars can "make it" in the long term the terrain is bad for these vehicles. Polique Canyon has yet to be graded, and yes it has some problems still although I think they can be mostly avoided.
So to answer the OPs question; yes you can make it to the South Parking Area in a Prius...