Air dams that are under the bumper create more down force than reduce drag, straight down from the tip is better for reducing drag as said.
The Porsche adjustable front spoiler has three modes
-street, high for curbs n speed bumps or w/e
-sport, low for aero n downforce
-top end/mph, low sides & raised center
Sure funny cars are the whole front but they also got nothing under and the body really and it comes off so it's the only practical option. And handling cars want downforce. I looked into this awhile back for drag racing and my conclusion was in front of the forward tires are important for normal cars straight-line aero and it only really starts to noticeably help somewhere above 110mph. On a drag car the front tires are skinny but any suspension that hangs is also a concern. Rear tires stuff has slowed down a lot unless they stick out on the sides. I'd try a low front tip air dam or a sides only and belly pan.
Remove your side mirrors, antenna or anything that sticks out.
I know as much as I can learn and try to keep an open mind to anything!
If I didn't overthink stuff I wouldn't be on speedtalk!