If we're looking for meaningful takeaways, there are a few things that most people can agree upon:
- flat and smooth bottom
TRD Griffon got this right:
- low and long front splitter
This is dependent on your application and suspension setup. The goal is low without scraping.
- rear diffuser
This reduces the vehicle's wake, and the updraft effect can be enhanced with a trunk lid spoiler
- rear wing
This adds downforce, but you need to design a setup that has a direct load path to the frame. TRD Griffon uses a carbon lid, which transfers the downforce better than flimsy sheet metal.
- remove engine bay and wheel arch pressure
Giving the (relatively) high pressure air an exit can usually be done in a way that doesn't add lift and improves cooling in those areas.