I have been doing another batch of videos.
Ducted radiators:
https://youtu.be/P7Wh1XoystM
A good way of measuring car lift (and lower lift usually equals lower drag!):
https://youtu.be/wmleR-BNOV8
Trailing vortices and drag:
https://youtu.be/yCrXHldsKLA
Vortex generators - fads and fashions:
https://youtu.be/1OzHIsRsS40
Reducing rear vision mirror drag:
https://youtu.be/wDB2y0LuBek