Waspswatter....my man, you seem like a great person so far, so here's what I got for you. It's a paper written by a smart guy who got a Masters Degree asking the questions you are here and then writing a thesis. Imagine that? You don't have to take my word for it, or anyone elses here, just trust in Feysal.
Read This
Pay Real Close Attention to the last paragraph on page 84 and the chart on his page 85, (adobe's page 103).....ask again what a 10-12° cap does for you.
This was why I suggested what I did before, cause I was thinking of this paper, by a smart guy, not just making stuff up.
Here's a pic of a Ranger with a green 10° line and a red template imposed on it....ironic that they meet over the top of the tailgate??? I think not.
VG's are worthless on ground based lumpy butt vehicles going 70mph, think udders on bulls.