A car in the supermarket carpark
 

The more I looked, the more fascinated I became.

https://www.youtube.com/watch?v=pvLkQRsNLF4

In another thread I asked about modding the hatch on a Geo Metro, and this is exactly on point, so thank you.

• The lip: better, worse or an evolution of the Gurney flap?
• The fences: an area of re-attachment after the roof rack hardware?
• The green arrow: Was that a step or a slot beneath the arrowhead?

1. I don't understand the reference to a Gurney flap. A Gurney flap is used on a wing. This is not a wing, so I cannot see how anything on this spoiler can be referred to in that context. Re the lip, 'better' or 'worse' in what regard? Lift? Drag?

2. The longitudinal strakes, I suggest, perform the function I ascribed to them in the video. I don't see the longitudinal filler strips doing much to cause separation.

3. Step not slot. And such a small step it would be of no consequence I would think.

1. Can you propose a word to describe a small scale disruptor to modulate the flow around a larger feature? 'Gurney flap' wasn't named for an airplane pilot.

2. I though it was a weak point due to the average 7° crosswind.

3. Okay. I suspect it's a manufacturing issue, avoiding trying to fit to the hatch edge.

1. Spoiler lip

2. Where did you get that figure from? That's much higher than any data I have seen.

3. Yes I think so - need a minimum thickness in the moulding.

Don't know. A recent thread. Google's search function is no help — Six pages on 'crosswind yaw' and no way to sort by date. And it hits on UTF-8 when I search on '7° crosswind'! I'm pretty sure you were in the thread.

A DuckDuckGo inurl: search find one hit, no numbers.

I'd care more, but it's sunny outside.

The median yaw that Nissan found for the US was 4 degrees.

I found it. It was in a reference hearsay by you-know-who.

ecomodder.com/forum/showthread.php/hidden-real-drag-coefficient-39010.html#post640594

7 degrees (what you said) does not equal 7 mph (what Aerohead said).

You're right, of course. It was in imperfect recollection. Hopefully the cite will appear.