Engine Noise Upon Shut Off

Probably the best way to find out what's making the noise would be to go to a Chrysler specialist for an opinion. Your noise complaint is too vague for me to try to help you from here. I'd have to hear it myself. Here's a directory link for you: http://repairpal.com/chrysler-repair-in-austin-texas

It's the alternator overrunning clutch pulley. An easy fix, but requires a special tool.