I went and checked out a 2013 300c with the 5.7 in it, the car was beautiful other than a louder than usual tap coming from the driver side of the engine. I'm well aware of the infamous hemi tick, my current 06 300 has it as well as my dad's 04 ram but, this tapping was coming from the drivers side of the engine. It got followed the rev curve of the engine but under when I got on it on the test drive you couldn't really hear it. My worry is that a lifter may actually be bad as the car's oil level was fine. I'm not sure how long the car sat before I went and looked at it as I've heard that when the cars sit for a while it can take time for the lifters to get good oil again. The dealer said they'd look into it and get back to me about it but even after consulting my mechanic I'm not so sure about what to expect. I've seen many posts and videos about it being possible lifter/camshaft failure along with others saying it may just be a manifold leak. The car idled fine and had plenty of power with no misfires or anything really tell tale about the tapping. If anyone has some insight or advice from their own experience I'd greatly appreciate it.