The car still looks pretty organic. The front is weirdly curved and the back is wavy for instance. Good ol' Sub-D is in my opinion still much better for hard surface stuff. Zbrush will make your topology a mess and cleaning the model will take as much as time as if you would do the Sub-D in the beggining. Just my two…
Honestly the more I learn about hard surface modeling, industrial design, and how the world around us built in general the less impressed I become with Zbrush hard surfacing. The tools are very limited and down right awkward compared to other approaches for hard surfacing. The curves are a joke, especially the clip curves…