It's the Magnusson-Moss Act. It deals with warranties, but does not mean what most "tuners" seem to think it does. Since someone brought it up, I'm going to get on my soapbox for a moment, even though none of this necessarily applies to TRD parts.
The Magnusson-Moss Act DOES NOT make it illegal for a car manufacturer to provide in the warranties for the cars it sells that installation of aftermarket or non-OEM parts may void the warranty. Specifically, what the Act makes illegal in this area are so-called "Tie-In Sales" provisions, which basically require the consumer to purchase additional parts or services from the manufacturer to be able to get warranty service.
This thread was good motivation for me to grab my warranty booklet and read through it. If you'll look at page 11, there's a short list of "What is Not Covered." IMPROPER installation of aftermarket or non-OEM parts could fall under several of those provisions, including "negligence," "misuse," "alteration or tampering," etc., even if the provisions precluding installation of non-Scion Authorized Parts might not be enforceable. Also, installing too much performance-enhancing stuff might very well be "overloading," which would also void the warranty according to its terms.
In fact, one of the specific examples provided by the FTC (see the link below) of a
valid warranty provision is: "Improper or incorrectly performed maintenance or repair voids this warranty." Maybe an improperly installed short-ram cold air intake (or one with improper specifications), voids your warranty; maybe it doesn't. I personally am not sure that it's worth the risk.
Even with TRD parts, if you don't get them installed by the dealer, you're running the risk of them saying it was "improperly installed."
The bottom line, though, is this -- if you bring your Scion in for repairs, sure, if your dealer claims that your warranty has been voided by something you installed or had installed, your dealer may be in violation of the Magnusson-Moss Act, but do you have any idea how difficult, expensive, and time-consuming it would be to sue Toyota? They have a lot more money, a lot more (and probably better) lawyers, and infinitely more time than you. Your case could go on for years. In the meantime, you would still have a malfunctioning Scion that needed fixing, and you'd pay for it one way or the other.
I don't know what I'm advising exactly, but I just thought it might be helpful for everyone to have the facts in mind when making the decision whether to mod or not to mod.
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Here's a link with some information on the Magnusson-Moss Act from the FTC:
FTC on the Magnusson-Moss Act
