for instance; unplug the meter and a/c amp on a newer nissan and the thing wont start. More than likely they will require that the system be integrated into a primary control unit like the ecm, bcm, or srscm. Most all cars now use a controller area networking system to communicate with each other, and knocking one unit out of the mix can throw the whole network down, then all kinds of crazy shit happens. Every day I wrench on newer Nissans makes me glad I own a classic!
......And just as they're about to catch me.....Twin......Turbos......Kick.......In!