Vehicle owners are often faced with the need to protect the body or give the car a more aggressive and stylish appearance. One of the first questions that arises is the correct terminology. Car door trim is a general name for a whole group of elements that can differ radically in their functionality, installation location and materials of manufacture.
In the automotive world, there is no single word that describes all possible options. Depending on where exactly the element is located - on the threshold, on the handle, on the inner panel or on the outer edge - its name also changes. Understanding these differences is critical if you want to buy the exact part you need rather than getting an unnecessary accessory.
In this article we will look in detail at what the different types of linings are called, what they are made of, and why a modern car needs these elements at all. You will learn about the intricacies of choosing materials and installation features, which will help you avoid common mistakes when tuning or repairing.
Thresholds: protection and style
The most common type of external elements, which drivers often simply call “overlays,” are sills. Threshold plates perform a dual function: they protect factory paint and metal from chips, scratches and corrosion, and also serve as a decorative element. When getting in and out of a car, this area is subject to maximum mechanical impact from the soles of shoes.
Such elements are most often made of stainless steel, aluminum or durable plastic with a chrome finish. Metal options, especially from stainless steel, are considered the most durable. They effectively resist the reagents that are used to sprinkle roads in winter, and do not lose their shine for years. Plastic analogues are cheaper, but can fade in the sun and lose their presentation faster.
It is important to note that door sill covers can be universal or made specifically for a specific car model. Universal ones are attached with glue or double-sided tape, while model ones often have complex geometry that follows the curves of the body and may require more complex installation.
⚠️ Attention: When installing metal thresholds, make sure that they do not block the technological openings for draining water from the threshold area. Blocking the drain will cause the body metal to quickly rot from the inside.
Covers for door handles and locks
Door handles are an area of constant tactile contact. Every day, the driver and passengers touch them dozens of times, which leads to micro-scratches, scuffs of varnish and even chipped paint around the keyhole. Door handle covers designed to solve this problem while maintaining a neat appearance of the car.
Most often, such elements are thin frames made of plastic, painted chrome, or made in body color (the so-called overlay). They are glued directly on top of the factory part using a special automotive sealant or 3M double-sided tape. This allows you to hide existing defects or prevent their appearance on a new car.
Overlays with additional functionality deserve special attention. For example, there are frames with integrated lighting that light up when the door is opened, or elements with a brand logo that change color. Such parts fall into the category of easy tuning and do not require intervention in the car’s electrical system unless a complex connection diagram is provided.
Before gluing any decorative elements, be sure to degrease the surface with alcohol or special anti-silicone. Remaining wax or polish will prevent the glue from setting, and the pad will fall off within a week.
Internal door cards and heel guards
The interior of the car also requires protection, and here the linings play no less important role than on the outside. Interior door panels, or panels, often suffer from impacts from shoe heels, knees, or sharp objects that the driver and passengers may be holding. Protective covers for door cards (often called "heels") are made of thick rubber, plastic or carbon fiber.
These elements are installed at the bottom of the interior panel, taking the brunt of the impact. In addition to their utilitarian function, they can visually expand the interior space or add a sporty accent if made in contrasting colors. For premium cars, such linings are often finished in leather or Alcantara, blending harmoniously into the overall interior design.
Another type of internal lining is protective films or plates in the area of door handles that open from the inside. Constant rubbing with your fingers will wear away the texture of the plastic or leather over time. Transparent polymer overlays allow you to preserve the factory condition of the materials, remaining almost invisible to the eye.
Why does white plastic turn yellow?
White or light-colored linings in the interior may turn yellow over time when exposed to ultraviolet radiation. This is a chemical reaction of plastic components. To slow down the process, use protective compounds with UV filters every time you dry clean the interior.
Moldings and decorative elements of the body
When talking about what the door trim is called, we cannot fail to mention moldings. These are long decorative or protective strips that can run along the bottom edge of the door, separate color zones of the body, or frame windows. Moldings protect the body from impacts from neighboring cars in the parking lot and from stones flying from under the wheels.
There are several types of moldings:
- 🛡️ Protective: made of dense rubber or soft plastic, they have a significant thickness to absorb shock.
- ✨ Decorative: thin chrome or matte stripes that change the visual perception of the car’s silhouette.
- 🌊 Gutters: elements integrated into the door design to drain water, often combined with a decorative function.
Installation of moldings requires special care. While the protective rubber element can simply be glued or pushed onto the edge, decorative chrome strips often require perfect surface preparation. Any speck of dust under a thin sticker will be clearly visible. In addition, it is important to take into account the thermal expansion of materials: in winter the plastic contracts, in summer it expands, and if micro-gaps are not left, the lining may become deformed or come off.
☑️ Check before installing moldings
Manufacturing materials: pros and cons
The choice of material for overlays directly affects their durability and appearance. The modern market offers many options, each of which has its own operating characteristics. Understanding the properties of materials will help you avoid disappointment after the first wash or winter season.
Below is a comparative table of the main materials used for the production of automotive trims:
| Material | Durability | Appearance | Resistance to reagents |
|---|---|---|---|
| Stainless steel | High | Metallic shine, engraving | Excellent |
| ABS plastic (chrome) | Average | Metal imitation, glossy | Good, but possible chips |
| Carbon | Very high | Sports, weave texture | Excellent |
| Aluminum | Medium/High | Matt or polished | Requires anodizing |
Stainless steel remains the leader in reliability, especially for thresholds. However, it is heavier and more expensive to produce. ABS plastic with galvanic chrome coating is the most popular budget option, but it is afraid of shocks and severe frosts when it becomes fragile. Carbon are chosen by those who are willing to overpay for exclusivity and maximum strength with minimal weight.
⚠️ Attention: Cheap plastic with a chrome-like coating can begin to peel off after just six months of use. When purchasing, pay attention to the thickness of the chrome layer and the presence of a protective film on the product.
Features of installation and maintenance
The quality of installation of the overlays determines how long they will last and how they will look. Even the most expensive carbon fiber element can be damaged by improper installation. The main rule is surface cleanliness. Before gluing, it is necessary not only to wash the car, but also to use special degreasers.
The installation process usually looks like this:
- Dry fitting of the element to check the geometry.
- Cleaning and degreasing the installation area.
- Applying a primer (adhesion activator) to the body and adhesive surface.
- Heating the parts with a construction hairdryer to a temperature of 40-60 degrees.
- Removing the protective film from the tape and carefully gluing it with a clamp.
After installation, it is recommended not to wet the car or expose the pads to stress for 24-48 hours so that the adhesive is completely polymerized. Caring for the linings is simple: wash them together with the body using a soft sponge. For chrome elements, there are special polishes that restore shine and create a protective layer.
The main secret to the durability of the linings is not so much the material as the quality preparation of the surface before installation. 90% of peeling cases occur due to poor degreasing.
Is it possible to glue overlays in the cold in winter?
Strongly not recommended. At low temperatures, the adhesive base loses its properties and the plastic becomes brittle. If installation is necessary, the car must be kept in a warm garage (+15...+20°C) for at least several hours before and after the procedure.
How to remove old trim without damaging the paint?
Use a hair dryer to heat the glue and a special thread (or fishing line) to carefully cut the element. Glue residues are removed with anti-silicone or a special remover for bitumen stains, but you must act carefully so as not to dissolve the body varnish.
Do pads affect aerodynamics?
Decorative overlays of minimal thickness have virtually no effect on aerodynamics. However, massive sills or wide moldings can create additional air turbulence and slightly increase fuel consumption at high speeds, as well as increase wind whistle.
Do I need to remove the handles to install the covers?
In 95% of cases - no. Modern overlays are designed as overlays that are glued on top of existing parts. Removing the handles is required only in rare cases of deep tuning or replacement of the mechanisms themselves.
Is it true that under the linings the body rusts faster?
This is only possible if the installation technology is violated. If moisture and dirt get under the lining, and air access is blocked, corrosion can develop covertly. Therefore, it is important that the adhesive base blocks access to water, and that the edges are securely glued.