I've been on Old Dale Road both into and out of the park, and both Pinkham Canyon and Berdoo Canyon from the park into the Coachella Valley. Old Dale can offer a navigational challenge (to the navigationally challenged like me) when exiting the park northbound, but seemed easy going south. Berdoo and Pinkham can have short sections with embedded rocks. No problem for stock trucks but lower AWD cars will want to be careful in those short sections. The NPS visitor center often tells people the road is washed out and impassable when it's perfectly fine. There's also Black Eagle Mine Road inside the park; I went part of the way up it once. It was "paved" with embedded rocks \and featured somewhat bleak scenery.