Good Day guyz.....

I'm a newbie, I got my toyota vios 1.3e (2008) just a week ago, and there are lots of questions in my mind that I want to ask, pero, ito muna....

My question is regarding rustproofing, and btw, this is my first car in my entire life, even my family never got a brand new car before, puro second hand lang... anyway, my question is: How can you tell that a car undergone rustproofing process, does
it come with a sticker? kasi yung officemate ko, meron sya sportivo, meron sticker sa likod (rustproofing), I'm just wondering kung na rustproof ba talaga yun, kasama kasi sa bayad, pina rustproof ko na....

Hope you guys can help me on this, especially those vios 2008 owners.....\

Thanks.....