Try an automobile locksmith. They can get you going for about half what a dealer charges and they come to you. Otherwise as Steve suggested... off to see a dealer.
With modern cars it takes 2 administrative keys to program a third key, without special equipment. You need to have 3 administrative keys so if you lose 1 you can have another cut and then authorize for use in your car by using the other two.
Answers & Comments
Depends on the car you may be able to program replacement key yourself. Some cars like MB require dealer to program your car to recognize new key.
Try an automobile locksmith. They can get you going for about half what a dealer charges and they come to you. Otherwise as Steve suggested... off to see a dealer.
With modern cars it takes 2 administrative keys to program a third key, without special equipment. You need to have 3 administrative keys so if you lose 1 you can have another cut and then authorize for use in your car by using the other two.