We recommend that you do it every year to keep your vehicle in optimum rust protection. If you run your finger underneath the vehicle and you get a good coat of oil on your finger, you should still be good. You could do it every other year, but if you are someone who is serious about keeping your vehicle protected, then once a year is best. 

Now. Your vehicle isn't going to wait to try to rust until you get it coated... People typically think about doing it right before winter because of the salt on the roads. But actually salt does more damage on your vehicle in the summer than the winter since salt does its worst damage when it is warm. It is good to do it before winter, but spring is also a great time to get it done. 

While we try to be careful not to get too much oil on, you will probably get some drip-age on your garage floor. Other customers have said that it does not stain your concrete and is easily washed off. If you are concerned about it, cardboard works very well to protect your floor. Spread some out on the floor before you pull your vehicle inside, until the oil stops dripping. 

Both oil and rubber undercoating are designed to help keep the moisture away from the metal which helps to keep it from rusting. One of the challenges with using rubber is that if you get any holes in the rubber or if water is able to get in behind the rubber, then the rubber acts as a barrier to keep the water in and the metal rusts out. Oil spreads and it is harder for it to get "holes" where rust can get in. If you have a weak spot in the oil, hopefully you hit it the next year and you are still protected. 

I have heard from different people that have seen what happens when water gets behind the rubber and so I have decided to stick with oil instead of rubber. Here is a link to a YouTube video with more info on it. Rubberized Undercoating Will Destroy Your Car!

Typically we think about salt damage on our vehicles in the winter because that is when we are driving in it. So people tend to think about preparing for it in the fall. The worst time for salt damage is warm temperatures. Salt corrosion speeds up when it gets warm. So when you pull your wet/salty vehicle into your warm garage, the salt is getting to work. When the temperatures start to climb in the spring, the salt is getting to work on your metal. So yes, getting your vehicle undercoated in the fall is great! Getting it undercoated in the spring is great too so it is protected during the summer. Normally people can get by with once a year, but if you really want to be careful, doing it fall and spring would really protect your vehicle. 

No we do not. Having said that, we do try our best to stand behind our work. If we damage something while working on your vehicle we will try to do our best to get it fixed. The reason we don't offer a warranty as such is that it is hard to quantify. How can we decide if the rust on your vehicle is because we didn't do a good enough job, or because it was rusted some before we started undercoating it, or numerous other things that are outside our control.

We can't guarantee a rust free vehicle after you have used us, but we are confident that your rust issues will be significantly less than if you had not gotten your vehicle oil undercoated. We try to do our best at protecting your vehicle, and our product has worked for years for others and we are confident it can work for you too. 

Finally everything in our world wears out and we can't stop it because we live in a fallen world, but we can do our best to use what we can to slow that process down and keep our things in as good a shape as possible. 

We can't guarantee that it will stop the rust, but our oil is specially created for oil undercoating and it has rust preventative properties in it and it is also a penetrating oil which helps it to penetrate into the existing rust and corners helping to really slow the rust and in some cases almost stop it. 

Since our oil is a penetrating oil, you don't necessarily need to get the salt off before hand as the oil will penetrate through it. Having said that, if you bring your vehicle in for the first time right after having driven a lot on de-iced roads, and there is a lot of salt build-up it would be good to run it through a car wash that has an under spray feature to help get the bulk of that salt off. If you do that, YOU NEED TO MAKE SURE THE VEHICLE IS DRY before bringing it in. Oil does not stick to wet metal very well. It will some, but you won't get the same quality of job as if it was dry. 

Your aluminum vehicle won't rust, but what they didn't tell you is that it will corrode. All metals will breakdown when exposed to salt. Some will rust, and others will oxidize and so you still need to protect them with oil or paint to keep that from happening. 

Here is the "scientific" explanation.

It is a full-bodied neutral mineral oil based rust preventative and penetrant lubricant developed for use as a corrosion protectant in automotive and commercial settings. Such as "oil undercoating." 

This product utilizes the latest cutting edge technology in water impervious base stocks, rust and corrosion inhibitors, and plasticized  polymer tackifiers that allows for uniform film thickness and ease of application while leaving a tenacious protective film to any surface applied. 

This durable product prevents and in many cases slows and halts oxidizing rust in the harshest of winter climates. 

You can if you want to before you bring it in to remove the extra dirt and grime, but your vehicle NEEDS TO BE DRY before you bring it to be undercoated, that way the oil can stick to the metal better. 

We recommend that you stay away from spraying the underside of your vehicle after it is coated because obviously the more you spray away at oil, the more chance there is that it will remove some of the oil. So for optimum performance, don't get the bottom of your vehicle sprayed so the oil layer doesn't get weakened.