why aren’t cars protected underneath? Why aren’t they enclosed in some kind of cowling or shield? Would that help to prevent damage and rust? Is there any way to enclose your car in a shield? Would it help anything?



why aren’t cars protected underneath? Why aren’t they enclosed in some kind of cowling or shield? Would that help to prevent damage and rust? Is there any way to enclose your car in a shield? Would it help anything?

In: Technology

Cars are a combination of compromises, additional protection comes with additional weight and cost; so there needs to be a high demand and benefit for such a change.

You can add an oil coating to prevent rust which can help. The issue with a cover is if water and salt slowly get under there over time they would be hard to wash off and would end up staying and causing rust just as much as if the parts were exposed. Also, there are hot parts like the exhaust that you wouldn’t want to cover up to avoid too much heat staying in the car and possible fires. And it would make maintenance more difficult and expensive.

Lastly it would add to the cost of the car. If you have an old car you’re probably wishing they’d done more from the factory to make it last longer. But *if you were buying a new car* would you be willing to pay more for a car that will last longer? The manufacturer only cares about selling you a new car, not how long it lasts you. Customers will demand cars that are reliable and will pay more for cars they think will last, but this has its limits.

Some vehicles are.

For many environments though, a bottom body skin could be problematic. It would slow down drying when moisture inevitably gets in. And may even collect water and debris. It might be difficult to keep clean enough to prevent clogged drainage holes, especially if you live in a climate where they commonly salt and sand the roads. For mechanics without access to a lift, it would be a huge pain getting it out of the way to do anything.

Off road vehicles often have metal skid plates under sensitive parts like the engine and transmission. The idea is to prevent large rocks from damaging the drivetrain. They don’t care that much about hitting the floor or frame as it won’t cause immediate problems.

Many race cars have plastic or carbon fiber plating under the car. Although this is not there to protect, it aids aerodynamics (a flat bottom creates less drag). In fact, some new cars come with this to help improve fuel economy.

As other have said, plating won’t really help rust but metal plating will help prevent immediate damage. However, the kind of damage it will protect from is when a tall, pointy object gets under the car. This really only happens when trying to drive over something. So it’s not really a problem that happens on the street.

EV are paradigm shifting the transportation industry. All the reasons so far provided for NOT under shielding vehicles are irrelevant.

So you buy a new one when it rusts out. Nearly all business don’t build the absolute best product, because the return is not worth the cost of making it better. Business are about making money and not necessarily about making the best product for the consumer or the environment. Additionally there are many places that do not use road salt and the vehicles last decades with very minimal rust.

Many new cars have shields that protect many parts. There are also shields on brake rotors, splash guards and more. Rust and corrosion is still an issue for those in the rust belt. Stuff is better, but still seems to be planned obsolescence. Cars used to be trash after 60,000 miles. Now an engine/transmission should last 200,000 miles with maintenance. I just lost a 20 year old truck to rust that was going to require a “frame off” repair.


Our Volkswagon Tiguan has covers under the engine and front suspension.All of it needs to come off to drain the oil.

A lot of newer and more “higher class” cars do have some kind of covering underneath actually, for pretty much those reasons.

However it is pretty annoying for for inspections because you won’t see any rust etc.

It is not uncommon to have an undercoating in areas that are exposed and that could rust. As other people have mentioned, skid plates are totally a thing too. If you really wanted though, you could have bed liner material applied to the underside of your car. It’s not going to make a big difference, but it could protect against corrosion and reduce damage from road-bed collisions or collisions with small objects that your car may drive over.

Corvettes have plating along the entire underneath. Makes it a hassle to fix them. Plus its harder for you to detect leaks without taking the plating off. Undercoating is what they have to help combat that issue but you need to reapply when you replace a part. And that can drive the price of repairs way up.