The Act does not require the dealer to prove anything, it allows for free arbitration for you to present your side to the Arbitrator and Ford to present theirs. The manufacturer cannot be expected to test every mod and combination of mods and replacement parts. Normal replacements parts have the third party companies that make them to prove they meet specs. Things like oil,brake parts, hoses and filters are accepted easily by this law. Any mods made that alter the performance or emissions of the engine (other than certain Mountune parts for Ford) are an automatic warranty killer for the powertrain. If you change the motor mount to a stiffer one they have the right to deny NVH complaints. The Act allows for third party parts as long as they meet the same specs as the part they are replacing. It is not up to Ford to test every engine mount out there, the maker must provide the proof. Many people wrongly think it requires the dealership to do something, it does not force them to do anything. You can be sure if Ford takes it to arbitration they will have a ream of engineering documents to back up whatever the claim. If your beef is with the dealer they don't even have to show up for a meeting. The Act is between you and Ford. The dealer is not Ford,they are a private business or Corporation, they do not warrant your car, Ford does. So your best recourse with dealer problems is involve Ford directly through Customer Care to advocate for you with the dealer. If the issue is not resolved then you can take Ford to Arbitration. The purpose of the Act was to prevent the car companies from saying you have to buy parts from them to keep your warranty. You don't as long as they meet the same specs. You are free to use a brand XYZ oil filter, but if it fails and causes an engine failure Ford will not repair your car, however XYZ may if like the majors they have a warranty. This is why some people stick to Ford parts, if they fail it is Ford's problem, not yours and XYZ company. Not that I have ever had a defective oil filter of any brand!