The easiest way to replace a lost automobile key is to contact either an accredited locksmith or your dealership. The dealer can order a replacement set of keys for your particular vehicle, while a locksmith can produce a set of keys that work by examining the locks and ignition.
Electronic keys and transponder keys generally require a trip to the dealership to replace due to the technology involved. These keys must be programmed to provide the correct code to start your car, and in the case of stolen keys, the car itself must be reprogrammed to prevent theft. Some electronic keys can be replaced by a locksmith, but you may have to make several calls before you find one that services your particular car's ignition system.