Aerohead's comment inspired me to put more thought/effort into my design. Definitely going with rounded corners. I decided I want to run some actual CFD analysis on the Ridgeline but I was unable to find an existing CAD model of the truck, so I started looking for scale models, which are almost as scarce. My plan is to use the 3D scanner at my local maker studio to get an accurate CAD model without having to go through the effort of modeling the truck from scratch. Apparently Matchbox made very limited quantities of it ten years ago and I got lucky to get for $5 the last one in stock outside of eBay it seems. (Plus my inner kid is super excited to have a new toy car!) I'll have to modify the model some, mostly just downizing the wheels and modifying the underbody accordingly.
Honda Ridgeline Overland Crew Pickup Truck - Global Diecast Direct
I've yet to decide whether to use Solidworks' or Autodesk's CFD but it will likely be one of those. At first I really wanted to run a optimization program for an aerocap like that 2003 thesis from the Naval Postgraduate School, but... we'll see.