Everyone is saying that it's ridiculous because Lee was out in the car for days.
But actually, he wasn't.
Lee's eyes flicker open twice. The first time they open, you can hear the cop screaming and zombies feeding. The second time they open, which everyone is saying is hours later, you can actually still hear the cop yelling for help and flesh tearing. I don't think it takes days for a guy to die when being devoured by walkers.