Quick note on grid when I ran it in group 3: I think the only issue I came across was the large group and long overlap causing people to get nervous about whether they'd missed their run, and there weren't many of those. I have a system that keep everything smooth, organized, and consistent so that by run 2 everyone knows exactly what to expect (that's important). One-driver in A / two-driver in B is perfect for a balanced and smooth grid operation in an all-at-once event.
The way I run a grid like that is...
First time through, I identify a car in line A that's easy to pick out, roughly halfway, and with the driver hanging out near it. I'll be telling that driver I'll be pulling A and break before I get to him to run line B, so he doesn't get geared up just for me to walk to the other side. In this case, it was the red Z3. I use the same car each time for consistency, and so pick someone who doesn't look too much like a flake.

It's much more important to be able to pick it out easily than to be exactly halfway -- anywhere in the middle 1/3 is fine.
I finish off the group I've taken over from the previous grid worker, then start the new group at the far end of Line A first.
Then I go into the routine, which is the same for each pass:
- As I approach the bus end of a line, I make sure there's enough cars lined up to cover my walk to the other end of the line I'll be pulling from next.
- On the way back up I remind (tell first time) the "break" driver I'll do B before him.
- I finish the walk up to the far end of line A. I do this part of the walk briskly and in the middle of the road so I stand out as the person with the clipboard coming up to send cars.
- I pull cars from the far end of A and stop before the red Z3.
- I move to line B, pulling from the far end until line B is done, stacking the line a little at the end to allow time to walk back to the right place in line A.
- I go back and pull line A from the red Z3 to the end.
- When I hit the end of the line A, I go back and pull B again, stacking cars to allow for the walk.
- This second time through B, the line has to be stacked a little more because I'm going to be moving all the way to the far end of line A.
B line gets two runs for each A run, so everyone should finish run 4 on the same pass.
There are inevitable people who aren't ready when I get there. If they're at the car and just haven't geared up yet I mark them off and tell them to go when they're ready, and I keep walking. If no-one's at the car, I just walk on by and pull the next -- when they eventuallly realize it, they'll come find me, and I tell them to get their car and pull up by me so I can mark them off and feed them in when ready. The line sometimes runs a little long this way but it never runs short of cars, and no-one misses their run.
My ideal start line never gets shorter than 3 cars to allow a buffer in case I have to deal with an issue on grid. I generally shoot for one on the line and 3-4 waiting -- ideally the next car arrives as the one on the line launches, but I'm not *that* good.

Places where I can't really see the grid line well (like at the far end of A on Sunday) I try to time my sending a car with one completing the course to keep the line consistent. Greenville is the hardest, can't run the line long there and can't see it well; Danville is usually the easiest to see and keep at the right length.
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Martyn Wheeler
AXing Kit's '05 Mazda 3, #29 HStock
(when
The Gonzo Symphonic allows)