key question

The round key was trunk and glovebox only. The square key was doors and ignition. Since the grooves that run the length of the key were different, a trunk (round) key won't physically go into a door or ignition lock. If cut properly the later pentastar key blanks will work in the older locks since the main difference was the depth of the locks. The new keys have to start the cut as close as possible to the end of the blank...