Can I use a newer stock stereo in an older model car?

You would probably need an interface so that the ECM is happy , To save some aggravation but not money you could go to a pro stereo shop . I suggest you don't go through with it and just get something else to drive

The wiring is totally different so it is not going to be a plug and play, then you have computer issues, your existing computer might not even recognize a newer unit let alone interface with it. If your current system is malfunctioning I suggest you go with aftermarket systems. Car Toys, Best Buy, Crutchfield just name a few, plus you might have some local automotive sound centers.

Be careful, some vehicles have the security system and other things incorporated into the stereo. Before proceeding, do your homework. You don't want to end up with a dead vehicle because you tried to replace the stereo! Jim