I think that, in this case, "reliability" really means "durability". The FPD has a lot of issues with Chargers losing tie rod ends and needing alignments all the time. You can't hop curbs and railroad tracks when them like you could the tanks they used to have, the Crown Vics.
In most cases, heavy suspension components (like live axles and cast iron pieces) are undesirable, but in severe duty like that, you need up-rated stuff. The Chargers don't seem to have it.
One thing I like about the Hemi, though, is it's a relatively low density power engine, so there's a lot more mass and material there than it really needs for the power produced. Again, not necessary on the street, but in severe duty, more mechanical freeboard is a good thing. I look at a small turbo'd V-6 in police duty the same way I look at aluminum independent suspension in police duty...it seems like they're trying to get an awful lot of bang for their mechanical buck with that equipment.
