This was the response I received from Toyota in regards to my inquiry about if they undercoat at the factory. Enjoy. Also, basically reads to me like, “As long as salt, brine, gravel, or any other surface material is not to blame on the rust then we’ll cover it.” Seems about as worthless as the email it was sent through
“We have confirmed Toyota does apply an undercoating to the chassis, floor underside, sheet metal fitting weld points of the body, and inside of the wheel house to prevent rust and noise, as well as protect the body from gravel.
Additionally, Toyota does provide a Corrosion Perforation Warranty which is for 5 years unlimited mileage. This warranty covers any repair or replacement to the original body panels of the vehicle that are perforated as a result of corrosion and where such damage is not attributable to non-warrantable sources such as, but not limited to, accident damage and unrepaired surface corrosion. Corrosion other than perforation is covered for 3 years or 36,000, whichever occurs first. Corrosion due to external forces or damages caused by stones, gravel, salt, industrial fallout or pollution etc. is not covered.
For more warranty information, please see the Warranty and Maintenance Guide. A digital copy of this guide can be found at https://www.toyota.com/owners/warranty-owners-manuals/.”
“We have confirmed Toyota does apply an undercoating to the chassis, floor underside, sheet metal fitting weld points of the body, and inside of the wheel house to prevent rust and noise, as well as protect the body from gravel.
Additionally, Toyota does provide a Corrosion Perforation Warranty which is for 5 years unlimited mileage. This warranty covers any repair or replacement to the original body panels of the vehicle that are perforated as a result of corrosion and where such damage is not attributable to non-warrantable sources such as, but not limited to, accident damage and unrepaired surface corrosion. Corrosion other than perforation is covered for 3 years or 36,000, whichever occurs first. Corrosion due to external forces or damages caused by stones, gravel, salt, industrial fallout or pollution etc. is not covered.
For more warranty information, please see the Warranty and Maintenance Guide. A digital copy of this guide can be found at https://www.toyota.com/owners/warranty-owners-manuals/.”