Identification

Each car warranty carries different conditions and requirements. Typical actions or events that void a warranty are neglect or reckless use of the car, such as drag racing and totaled cars.

Considerations

Just because a manufacturer denies a claim does not mean the warranty becomes void. Some repairs may simply not fall under the conditions of the agreement, requiring the owner to pay for this maintenance, but the warranty remains active.

Misconceptions

Using third-party, or "aftermarket" parts does not automatically nullify a car warranty. The dealer must prove that an aftermarket part specifically caused damage in order to deny a claim.

Warning

While the Magnuson-Moss Warranty Act protects consumers from unreasonable demands in a warranty agreement, this does not give a person free reign to modify their car and still retain warranty coverage. Modifying on-board diagnostics, for example, makes it very difficult for a serviceman to diagnose a problem, voiding the warranty.

Tips

Always use the proper chemicals to maintain a car. If someone pours sugar in a gas tank, this voids a warranty, but so does using the wrong gas type. Consumers should also take their cars in for frequent maintenance, and keep any receipts and records.

Source:

Edmunds.com; What Voids Your Vehicle's Warranty?

Dummies.com; Keeping Your Mod's Warranty Intact