[California98Civic]

You should totally experiment.

Yes the eigth gen is beautiful. I think the 2006 Civic coupe is one of the best looking cars Honda ever built and I have long wanted one. And the backlight does have a better angle than a sixth gen or seventh gen coupe. But a sixth gen coupe is like 20 or 22 degrees. Your sedan will be a little steeper because the back end of the roof line is higher for rear passengers. But not a lot higher... At least an inch, maybe two inches, but that is all. Producing your own backlight Kamm with optimal compound curves and radiusing will be a challenge requiring experiment and revision. Honda had windtunnels and computers and professional staff. I think one of the reasons EM folks seem to go for th boat tail to succeed is because the greater possibility of big gains in the boat tail over the OEM makes it easier to get to a build that forgives design flaws. A Kamm cannot be as forgiving. Get it wrong and you may see no benefit.

This was prt of my problem with the box cavity, too. And I lost enthusiasm because I just did not have the time needed for testing multiple design mods. I would love to see you experiment. I believe I have the PDF articles I read for the box cavity (no longer freely available, IIRC. Send me a PM if you want them and we can exchange email addresses for the attachment. (That goes for any other EM member too who wants them).