My wife and I and another couple drove to Granada last week and missed a turn to our hotel. While we were trying to find our way back to the right road, a man on a scooter approached and offered to guide us there. We followed him in what seemed like a pretty round-about course back to the hotel. I gave him 5 euro for helping us but he DEMANDED we pay him 20 euro. He refused to leave and was becoming belligerent. Frankly, I was concerned he was going to do some damage to the rental car. Fortunately, the desk clerk came out and chased him away before we called the cops.
So if you happen to get of track in Granada, be careful when someone offers to guide you back to your hotel!