New cars since around 1990 have chip transponders in the key which talks to the computer. If you get a key copied and it is a transponder key and you copied it on a standard key it will shut down the computer and it will have to be towed to the dealer, which could cost you $1500 or more to fix. We have a unit which will decode the chip, copy it and load the information on to a new key blank. We can do about 75 percent of the cars with the chip, transponders.