Most foreign cars made today have codes somewhere.  Codes are usually stamped on one or more of the locks with the door lock being the most likely spot to find one.  The problem is that it can take a bit of work to get these codes.  Luckily, foreign car door locks usually use the whole key and not just part of it as American ones do.  Thus, even if the passenger door lock does not have a code on it, a complete key can usually be made once the lock has been removed from the door.  Removing the door lock yourself and taking it to a locksmith can save quite a bit of money.  With some patience and mechanical ability, a door lock can be removed using very few tools.

    In contrast, hardly any American made cars have any codes anywhere in the car and no single lock uses the whole key.  Thus other methods are required to make keys when a roadside service or dealership is unavailable to release codes.  Sometimes locks are replaced, such as with General Motors and Chrysler six cut side bar ignitions.  Some keys are made by impressioning and others by using try-out keys.  Most locksmiths prefer to impression keys whenever possible because it is the fastest method.  Too bad, since the keys usually don't work very well and the locks can be damaged.