Uncle Tony says Gen III hemi has inherent lifter lubrication problems. Agree?
I managed a police fleet for nearly 20 years. For my last 11 years before I retired, I switched the fleet to Chargers (when the venerable Crown Vics were no longer available).
The biggest problems with the Chargers were the front suspension bushings wearing out early and then of course, the cam/lifter problems with the Eagle engines. (Note: The agencies with the Ford Taurus and Chevy Caprices had WAY more problems going on than I did. The Charger was by far the right choice.)
Tony has some very good points that would be exacerbated by the high idle time that our Chargers endure. Unfortunately, I could not monitor every car often enough and the officers (with some exceptions) usually didn't report a problem until the check engine light came on. By then, it was because a cam lobe was entirely ground flat and the engine had a miss.
I did however, catch some cars from time to time early on when I would hear a chirping sound. The rollers were going bad in the lifter; it would seize up and just skid over the lobes. FCA always covered the problem, sometimes twice or even three times in a vehicles life cycle with us. (This was good, but it sure was a pain having a vehicle down for warranty) I had contacts deeper into FCA than just the dealer, but even those guys swore they did not know what the problem was. To this day, I don't believe them and I'm not there any more to see if some of the newest cars start having the problem. I suspect FCA has at least tried some changes, either with the lubrication design, or cam/lifter manufacturer.
I do know that the earlier cars have lifters made in Germany and they look like precision machined artwork. Don't know on the later cars. To my knowledge, unless things have changed, the SRT cars received forged cams and the 5.7s were cast cams. My personal suspicion is that it's an oiling problem, especially at idle, but I don't think anyone outside of FCA engineers really know for sure. It could also be a FEW problems like oil AND camshafts AND lifters, going bad individually, depending on the driver and maintenance situation. BTW, my cars had their oil changed every 3,000 miles, using a synthetic blend that met FCA specs.