Undercoat or Paint

[StockEngine]

Is undercoat ans rust proofing (usual freebie) the same?
Also, how long will it last, do i get another undercoat or rust proofing after "X" number of year(s)?
Thank you...

Take photos of the underbody of the vehicle on display for your reference.

If the car delivered to you and the underbody looks the same. Its called factory rustproofing.

Some even say the tire jack is a freebie.

Some even say you get a freebie of 5 liters.. ahem.

Worthless freebies