"Homeland Security" Veteran:

You must have two people or you will lose. For the first round defend the gas station. Make your way to Burger Town for the second round and defend there. Then for the third through fifth round STAY at the Taco place. The only entrance is the broken wall facing nates. Have one team mate sit there and have the other team mate sit in between the counters so he can cover the front and side. If either team mate is downed revive him behind the counters. Always deal with the vehicles last. This should allow you to easily beat it on veteran.