So the salesman told me any and all modifications done to my 14 Challenger RT have to be done at the dealership. What can or can't be done to my car to not void the warranty?
Your dealer just wants your business. You can have parts installed by anyone. Under the Magnuson Act, you have a right to install any after market part on your car. If you encounter a problem while under warranty, the dealer would have to prove that the after market part caused the failure. Read this FTC bulletin: FTC Validates Right to Install Aftermarket Parts | Specialty Equipment Market Association
I heard that putting an after market headers would void the warranty. But now I am not so sure based on what you provided or am I reading that wrong?
At that time I hadn't done anything. Since then I have a Mopar CAI. From what I've read here....as long as you keep the cats you good but it also depends on the dealership.
From that "Magnuson Act" link: "The dealer/vehicle manufacturer has the right to deny a warranty repair but they must demonstrate that the aftermarket part caused the problem." Here's the main practical problem with a loose/favorable interpretation of the Magnuson Act: Once a dealer/manufacturer denies you warranty coverage, in order to obtain satisfaction you will have to drag them into court in order to force them to comply with those Magnuson Act provisions...and, once you're there, with the manufacturer's essentially bottomless legal budget, they will be free to prove almost anything they want to. Lest we forget, the original purpose of the Magnuson Act was to protect your right to use aftermarket replacement wear/maintenance items (oil, filter elements, accessory drive belts, spark plugs, brake pads, etc.), not items that can potentially alter the car's as-manufactured certified performance. An example: It simply would not be fair to expect an O.E.M. to warranty the car's emissions performance when internal engine components, intake systems, exhaust headers/cats/mufflers, etc., have been replaced with aftermarket parts...unless those parts are also emission-certified by their manufacturers. Somewhere between "maintenance/wear items" and my example lies a huge gray, fuzzy area containing a definite demarcation line between what will be allowed and what won't. Do you have the time, money, and patience for a possibly extended legal battle to find out exactly where that line will happen to fall on your particular day in court? My point is, that either your claim or your legal defense fund had better have very strong legs if you plan on excercising your Magnuson Act "rights". See the above dilemma. Though, if you are choosing aftermarket headers that are certified by your car's manufacturer, you'll be good to go. If they exist at all, they'll probably be sold by your dealer, or on the O.E.M.'s website (MOPAR, etc.). Good luck...
The dealer gets called to court not Dodge as they are you gives their line of bull when you're in for service. They don't want to be there and they don't have lawyers on staff. Unless you really messed up the car once they get an lawyers letter they usually back down.