In all seriousness.....it works. Just a regular can of WD40 and hose everything underneath, When I do a very detailed cleaning of my car in the spring and fall I buy an extra large can of WD40 and spray away....it works for me. Anyways as far as rust proofing the bottom and Scotch Guarding the interior....I have a few friends that work at the dealership and they state it's a total rip-off.....don't do it and I agree. The bodys of the new cars are dipped into a chemical bath tank during assembly and this prohibits rust very well. The WD40 helps it out during the winter....places an oily coating over the metal. Like I stated I have been doing this for years and my cars look as if they are brand-new underneath. Maybe we'll hear some other methods from others.

 

Sorry, I didnt mean to come off as sarcastic or disbelieving!! I am just genuinely surprised that this works lol. And thanks for the advice, I was cringing when my local ziebart quoted me at like $250 for a lining
I think an underbody wash and a thorough WD coating this weekend will be on the agenda!

 

OOppps, I didn't feel you were being sarcastic.....I was emphasizing that such a simple and inexpensive task does so much....hard to believe. My cars still look as if they are new and the stickers under the car are still there.....even the "86" GT which once appeared to be a rusty junk.....the bottom is now black with no rust. Just spray it on a couple times a year. I looked at other cars (2001 monte carlo & 1995 S-10 Blazer) that don't get the WD40 treatment....they are not rusted out, but they don't look as new underneath either.....so even if you don't WD the bottom...you still shouldn't have problems.

 

And don't freak out when you see quite a few undercarriage components with a rust coating. Many newbie owners get upset when they see ANY rust. All of it is normal since many components are ferrous metal and the thin layer of rust actually works to protect the under layer.

 

Thanks again everyone for all the replies...there's some good info there. The WD-40 surprised me...but I guess it makes sense. I'm going to give it a try...

 

Ok....WD40...money well spent!!