Which performance accessories are recommended for a Chrysler 300?

TL;DR: Grab a cold air intake for better sound and throttle response, or look into a muffler swap if you want a deeper rumble. With $500, your best bet is starting with the basics. Most guys in the community go for a cold air intake first. It wont turn it into a track car, but youll notice a difference in how it sounds under load. I recommend the K&N 63 Series AirCharger Cold Air Intake System because it is an easy DIY install. It basically replaces the restrictive factory box so the engine can pull air more freely. Another solid option within that budget is upgrading the mufflers. A set of Flowmaster Super 44 Series Mufflers will give you that classic muscle car sound you are likely looking for. Just remember to save about $100 for a local exhaust shop to weld them in for you since it isnt a bolt-on job like the intake is.