I don't think we can take anything of spam_master's. Eor would need to give him a chance to react, and he's inactive, so he can't react.
Anyhow, the roof is being overrun with leaping zombies. We could probably make a break for it, but I don't know which way would be better to go. If you could get in a position where you could see our position from outside, that would be really helpful.
Also, I don't think we can get heavy boxes of ammo up to the roof. Would be better if you could just drive your car up right next to the rear of the store, somehow, but I don't know if that will be doable. The molotovs may have thinned out the zombies, but I suspect there are still a lot there.