....to and from airport and possibly other day trips?? For 2 early April, 2013
Zurich has such great train service to and through the airport that a car service is really not needed.
The train station is right in the airport terminal, and you can board a train the goes to Lucerne with no other changes. It is better than a car service.
Skip the car and ride the train. As I recall there is one train an hour direct from Luzern to Zurich airport. There are others if you don't mind changing in Zurich HB. While Zurich HB is a big station its really easy to change trains there. sbb.ch will give you the schedules.