Detroit Metropolitan Airport should be chosen (rather than Detroit City Airport).

Car Rental
Avis (734-942-3453 @ Airport) 800-331-1212
Hertz (734-941-4747 @ Airport ) 800-654-3131
National (734-941-7000 @ Airport) 800-227-7368

Airport Limousine Service
Commuter Transportation (734-941-3252 @ Airport) 800-351-5466