Dead Island Side Quests Walkthrough: Hit and Run
You get this quest from Omar Torres in the Hotel Bungalows area, Bungalow #17.
While in the hotel bungalows, watch for the exclamation mark and you should be able to find him easily.
Omar tells you some tall guy owed him money, and wants you to take care of this debt. Your goal is to find the guy and get the key to the safe from him.
Head to the bar following the instructions on the minimap. There will be a few zombies along the way but they shouldnt pose much problem in this case. Then you will get to a bar, and from there there will be a new clue, a trail of blood which you have to follow and leads you into a public restroom.
In that public restroom prepare for a fight - there will be a thug type zombie waiting for you there. This is the guy Omar wanted you to find. He is hiding in one of the stalls. It is best that you come into the restroom with your rage meter full, as this zombie can be pretty tough. If it kills you, just keep going back and have at him, rinse and repeat, until you finally kill him.
Once you kill the Zombie, loot the safe key from him and report back to Omar. Follow Omar to the other room and open the safe. This completes the quest and gives you the reward, as well as unlocking a new quest, Omar Escort.