1. Make sure to communicate with the rental company about the pick-up and drop-off location and time

Comparing makes a difference. The car I rented from European last time was handled very efficiently, and both pick-up and drop-off were super convenient. However, with Avis, the guy at the counter was on the phone for a long time before finally assisting us, and then it took ages with the paperwork. Returning the car was a big hassle too at the airport. We got lost, ended up in a paid parking lot and lost 40 NOK, all while rushing to catch a flight! The Avis office is very small and difficult to find, and even an Avis employee's sister, who is a taxi driver, couldn't help us locate it. Avis was very irresponsible in this regard.