I've settled for the low output Malkoff dropins in G2L bodies for the cars. Mine are M60LF dropins, but I would be just as happy (or happier) with M61LL dropins instead. Since these are single output lights, I prefer the longer runtime of the LL version, and might even consider the LLL version if that were still available.
Plus, the all Nitrolon lights are more comfortable to hold between your teeth to see when changing a tire... when it's raining... in the dark. Don't ask me how I know that.
I prefer CR123 batteries for this application, because they last a very long time stored, won't leak and damage the light. I've just had too many things get ruined by alkaline batteries in auto-destruct mode.
I think a good spotter would be a luxury, but I'd always choose less light and longer run-time if the SHTF. I'm more likely to need the light for close-in work- mostly to see what's in front of me for route finding and working on stuff.
My current EDC choice is an older style MD2 with M61, high/low ring, and delrin ring with pocket clip. Nice balance of throw and run-time, the low level is much more useful than I ever imagined, and couldn't live without it. The batteries do get used up more quickly than I'd like for a true SHTF light, so if I were doing it all over again, I'd run a M61L dropin with high/low ring in MD3 body for max runtime and most versatility in output.
I always carry spare batteries, as well, and love the PowerPax battery holders for that. I also use a short section of bicycle inner-tube with 2 CR123 cells inside that's attached to the light itself. It keeps two backup cells with the light, just in case of rapid bailout/grab-and-go situations.