When we rented a car from ACE Rental Cars, the Christchurch office gave us a marked map with a drop-off location different to what was in the contract. They explicitly instructed us to drop the car there. So we followed their instruction and dropped the car as indicated on the map. Then, they charged us an extra roughly $600 for doing so on the basis that we dropped the car to a different location than in the contract! We suspect they might do it more often to make profit on unsuspecting customers. You've been warned. Go to a better place.