What book is that?

It's from this book:

It's a very valuable reference, helped my decision process on headers, exhaust, suspension, aero upgrades...

http://www.classiczcars.com/forums/showpost.php?p=132080&postcount=13

I found this post by Carl to be helpful in deciding to get a front spook but not the rear.

I think it's a personal choice after the front "spook" (spoiler/scoop), but breaking up the rear turbulence is not a bad thing. I guess "spoop" would have been embarrassing.