In most of the automotive CNC applications that I've seen - and I've seen a lot of them! - the CNC machine gets set up for one job and then runs that job for eternity, day in and day out, until the end of the program. A lot of the time it's together with a robot that's picking parts out of a conveyor or some other fixture, and sticking that into the CNC and taking out the finished workpiece (which goes onto a conveyor leading to the next robotically-loaded CNC doing the next operation - and so on until the end of the line). The only thing the operators have to do is load up the infeed conveyor with blanks, and unload the racks of finished parts from the end.
Of course, the CNC still requires periodic attention for tool changes, etc.
The reasons for the automation aren't necessarily to eliminate manual labour but rather to control the risk of errors. Every workpiece goes through every machine, no operations are skipped, parts don't get loaded wrong or dropped in between operations or the wrong parts get into the machine, if a part fails at a check station (these are also automated) they can stop and fix the problem right away without making an entire batch of bad parts, etc. Of course, it helps that this allows the operators to load up the infeed and go on break while the robots and CNCs keep right on running through break or lunch.
The parts loaders and unloaders aren't making the good money. The process engineering and setup people probably are. The particular place that I have in mind is ALWAYS rearranging their process to make improvements ... and they just built an expansion that doubled the size of their plant, and that's right here in Ontario, too. They've been keeping food on the table here ... (I'm on the contract-engineering side of this)
