Spare Car Key Duplication

The time depends mainly on the key system rather than the blade. A plain mechanical key can often be duplicated within one visit, without extra electronic work. A transponder or remote-head key adds a cloning or programming step, done off the vehicle when the chip supports it and through the vehicle's own diagnostic port when it does not, with the diagnostic route usually taking longer. The locksmith can usually say which category your vehicle falls into once the make, model and year are known, before the appointment starts.

Somewhere other than inside the vehicle, since a spare kept in the glovebox solves little if it is the vehicle itself that becomes inaccessible. A bag that travels separately, a drawer at home, or a trusted family member all work. A passive proximity spare also benefits from a signal-blocking pouch during storage, since that kind of fob keeps broadcasting even sitting untouched in a drawer; a standard button-operated remote does not need the same pouch.

Generally yes, though it is worth mentioning any aftermarket system when you call, since a factory immobilizer that has been wired into a third-party alarm or remote starter sometimes behaves differently from the standard setup the locksmith expects. Knowing this in advance lets the visit account for it rather than discovering it partway through programming.