Cars today do not need additional rustproofing or undercoating. In some cases, applying these products can even make cars more likely to rust, so you're definitely better off without it.

Scotchgarding the interior is fine, and can give you some time to mop up spills before they stain the upholstery or carpet. You can Scotchgard your interior yourself with a can or two of Scotchgard spray, available at discount stores or auto parts stores for $6 or so a can. Just follow the directions on the can.

If I thought I had some special need for undercoating due to the way I used my vehicle, I'd want to shop around for it and purchase it myself, and then have it put on by someone I felt was going to do it right.

As others have said, you can buy scotch guard anywhere and put it on yourself also.

imo, undercoating has no value these days. Having paid for it once in the 70's, I don't even think it had value then. Manufactures are pretty good at treating metal so it's resistant to rust. You were smart to pass on it.

Frosts me that they always come up with these little extras AFTER you agree on a price for the car.

No thanks.

Today they shoot a product into panels that is a almost clear product that clings to the metal and does not run off like tar type does.

I get it done along with the Fabric protector.The dealership I buy from offer a 4 step package.

1Under Coating better known now as Sound deading
2Rust Proofing
3Interior sheild fabric protector
4paint sealer

I always take 2 and 3 and get it thrown in with the deal.So next time negotiate it in they will do it if they think you will head for the door.I also make them put on splash gaurds.The trick is to bring it up before closing the deal.Other wise they will wait until you say I will take it.Then spring it and other options on you.

Cars do not rust like they use to.But they can still develope rust problems later on and before there developing mechanical problems from old age.

Also there are a few spots under the car that I like to under coat also.But I do that my self with the spray cans available at Wallmart or where ever.I check these few places and do them over after a few years if needed.

In 2006 the term undercoating your car or truck,simply means it is being sprayed with a mixture of oil and transmission fluid.Oiling the bottom of your car can only help,it cant hurt!!!Oiling metal never hurts it!!!Undercoating a car in Ontario Canada is what I have just stated.It costs about 100 bucks.It can be done yourself with a spray jug and the right combination of fluids.

Keep animals away from your area,,trans fluid can harm or kill a dog/cat if they digest enough,much the same as antifreeze.

I take the rust proofing and fabric protection.I tell them to forget the under coating and paint sealer.I never pay for the rust proofing and fabric protection.I know there going to try to sell it.So before I shake on the final price.I throw them one last bone and tell them they must do it and put on splash gaurds and they have a deal.

I worked at a Buick dealership back in the early 90's. The package that people are talking about is a joke. Let me tell you about the undercoating. We got it in a 55 gallon drum. A green color liquid that I was told to fill a paint sprayer with and spray all exposed areas in the trunk, spray the strut towers and be sure to spray the exhaust. I asked why and was told so the customer smells it and knows we did the job. Now when I was a kid, my father had a 76 Buick Century that he had rust proofed at Zebart. They drilled holes in the doors and removed the trunk carpet and did a really good job. The car never rusted, we got rid of it when the motor died (Wish I knew how to fix cars back then) The "Paint protection" came in a little bottle called Vesco paint proof, all I did was to wheel it on. The "fabric protector just came in a different spray can, same 'ol Scotch Guard. Took me maybe 45 minutes to do all three and using less then $50 of supplies. They charged $500 + back in '92 for all this. I disagree with people that don't think you need rust proofing, the doors on my '92 Cavalier are rusted apart. But my '91 T-bird has just started to rust on the doors. A good quality rust proofing with a written warranty is a good investment. Dealerships like to tell you they will treat you like family, think about this...do you want to be treated like that???? Buy the car then get everything else after market, you will save big bucks.

Static

Of course they want you to buy it, the salesman gets about 90% of that money...