All newer cars are built to resist rust a lot better compared to cars from 3-4 decades ago. Pretty much every newer brand uses some form of factory rust protection. Whether it be galvanized steel, e coatings, wax compounds, or other means of protection.
These factory rust protection solutions are in use for the past thirty years or so, and the levels of refinement found on modern cars are extremely high. Brands like Mercedes, BMW, Volvo, and Porsche have been the most well-documented rust-proof cars.
But that’s not to say that these brands are noticeably better compared to a bunch of other brands. If you add any additional rust-protecting solutions onto your car, you are likely to never encounter rust. But the necessity of any additional rust-proofing is questionable.
If you do end up further rust-proofing your car, opt for a layer of ceramic shield, undercoating, drip oil spray, or paint protection film as these means of protection offer the best value for money.
Newer cars benefit from a sophisticated manufacturing process that usually encompasses multiple different means of rust protection. Brands such as BMW or Porsche have well-documented rust protection processes, and they also offer dedicated rust warranties on top.
The first step towards rust protection is the usage of galvanized steel. This is a process in which the outer layer of bare metal or iron is being coated with zinc to stop the panel from reacting with oxygen and moisture, or in other words, to prevent rust.
Besides galvanized steel, modern car brands also use special plastic-like wax solutions for all the out-of-reach nooks and crannies. Brands like BMW also dip their cars into a special bath in an effort of electrically charging the car’s panels to further negate the effects of potential rust.
Newer cars also take advantage of high-level manufacturing processes which ensure that all the body gaps are extremely small and precise. There are also loads of different paint protection solutions that sit onto the paint itself.
Older cars/used cars
Cars that are 30-40+ years old are the ones that are most likely to rust for several different reasons. Firstly, almost all of these cars never had any special rust proofing from the factory. The panel gaps are wide and uneven, often exposing vulnerable areas to the elements. And these problems only became worse throughout the years.
Furthermore, the age of the car itself is probably the highest risk factor when it comes to rust. A heavily used car has lost numerous levels of protection to all kinds of problems. The paint itself is probably chipped heavily, and so is the underbody of the car.
And these two places are usually plagued by rust. Only a small percentage of older cars are constantly being protected from rust due to their increased value. But the vast majority eventually succumb to the rigorous will of nature and start to rust.
If you plan on keeping your car for a long time, go ahead and consult a professional about all the different aftermarket rust proofing techniques. Without these, your car is likely going to experience some form of corrosion down the line if not protected from the factory.
Aftermarket rust proofing
Undercoating, drip/dripless oil sprays, electrical modules, ceramic shields, paint protection film… These are the most popular ways one can protect a car from rust. Undercoating is probably the most popular one of the bunch, and if done properly can protect your car for a few years before the need for a re-do.
Drip/Dripless oil sprays are also fairly popular, but you should opt for the drippy version as the dripless one usually requires you to disassemble or even drill into some car panels. All three of these cost around $100-200, and are well suited for temporary protection.
If you want to protect the paint itself, a layer of ceramic shield and a layer of paint protection film on top of that is the best possible way to protect the paint, and are even sometimes capable of protecting the underbody and many other car parts.
You can also check out dedicated electrical modules that if placed strategically send out a constant electrical current throughout the car’s panel. This module tries to mimic the e-coating some brands like BMW do from the factory. But these costs a few hundred dollars, and the levels of effectiveness are rather questionable.
Should I opt for aftermarket rust protection?
If you own a newer car, and you don’t plan on keeping it for decades to come, then no, it’s a waste of time and money. If you own a new car and you plan on keeping it for 30+ years, then it makes more sense to do it, but the necessity is still questionable.
In every other scenario, aftermarket rust protection makes more sense. But if you constantly wash your car, park it in a garage, and you don’t experience lots of salt and moisture throughout the year, rust is not all that likely to happen.
Can I do any rustproofing by myself?
Yes, you can. As mentioned previously, wash the car regularly, try to keep an eye out for any residue that might not wash away easily, and try to remove it without damaging the paint. You can also apply the undercoat by yourself.
You should gather all the necessary equipment first such as a car hoist, protective gloves and goggles, a primer, a can of black automotive paint, a grinder, and fine-grade sandpaper. First, you should grind all the areas, prime them in and paint them. After this, you can apply the coating evenly and wait for the coat to completely dry.
Can rust be fixed?
Rust can theoretically be fixed in 99% of situations, but sometimes it does not make any sense to do so financially. In worst-case scenarios, the car’s structural integrity is likely to be compromised, and this can be fixed but it’s time-consuming and expensive.
Lighter rust spots can be fixed easily just by grinding them out and protecting them afterwards. But the general rule of thumb is that rust should not be fixed if the car is not valuable enough afterward as some rust fixes could potentially cost more than the car itself.