don't start the truck until I give you the signal....?!?

well I was assuming the signal would have been the explosion to keep the creatures/zombies from following the truck or even heading toward it in the first place. however in the scene where you drops the flare into the spilled gas, the truck clearly had been started and was already moving away.....
other than that actually pretty cool and different kinda film - it would have made it a bit more interesting if in the end if it was Jack who sacrificed himself instead of Patrick to allow Patrick to have a second chance at being a father to Lu, that would have amped up the whole sort of human drama loss/redemption story vibe that was the bigger story line than the zombies.....