Here you go (not a GN though ). Not saying its perfect or anything, but its easy to get on and off and the seat belt clip at the top is high enough so it won't scrape your head when you're getting in or out.
This was a standard size net that when bought, so it should be easy to replace. You can measure it up and get a custom net so that the bottom follows the bar shape better for a cleaner look (not sure what the NHRA specs are for net sizes, mounts, etc).
No...I just went from the top of the hang rod to the bottom of the lower rod and told them that the loops need to stretch to that point. I gave them a perfect template with the dims writen on it along with my phone # if they had any questions. They did call and I walked them through what I did. All I did was folded up the template and fedex'd it to the contact I had talked with.