Again the point being, with the displaced threshold and an aircraft on a standard visual approach into that field, a car/SUV on the access road should NEVER violate the approach surface.
A quick trip to Google Earth indicates the road, Kelly Drive is 440ft from the displaced threshold of rwy 17. Even on the worse case 2%/28:1 glideslope* the clearance over the road surface should be 15ft!
Regardless of the actions of the driver the pilot of the C172 also shares the blame. He was simply too low on approach.
*VERY shallow for a VFR approach, the terrain at NW regional probably doesn't even allow it!