How are interior car panels installed?

Image Gallery: Car Safety Interior car panels protect the motors and wiring for windows and locks. See more car safety pictures.

Automotive manufacturing consists of many steps of production, including building and attaching parts of the vehicle during the assembly-line process. Interior car panel installation is just one of the steps, and it can include of a mix of human and robotic interaction to do the job right.

Interior car panels are more than just a covering for the inside of the door -- they have important functions like protecting the window when it's rolled down and covering electrical wiring and motors for windows and door locks. They serve as a barrier between occupants and the outside elements and are also engineered to reduce the amount of road noise an occupant hears.

In the past, installation of the interior door panels was done completely by people on the assembly line; now, robots are integrated into the auto manufacturing line, including the interior panel installation. Interior door panels ride down an assembly line and are fitted onto the exterior vehicle door by a set of fasteners; including plastic clips or adhesives [Source: Assembly Magazine]. The clips or adhesives attach the interior car panel to the exterior part of the door and form one complete door. Plastic clips allow autoworkers and vehicle owners to easily access the area behind the panel for window maintenance or electrical work after installation.

Depending on the manufacturer, part of the door may be assembled offsite and then added to the assembly line, or it may be assembled completely in the plant. The interior panels may be composed of several interior panel pieces that are connected to the metal frame of the door, or they may be one single piece. Multiple pieces allow for interior panels to be installed with consumer or manufacturer specifications or features.

On the next page, we'll learn about some different types of interior car panels.

Types of Interior Car Panels

As we mentioned on the previous page, interior panels can be made of many different types of materials, and each one is chosen for a different purpose. Over the past several decades, the interior car panel has received much more attention, as engineers focused on reducing the weight of vehicles to increase fuel efficiency. In addition to weight reduction, consumer demand for more luxurious interiors has also influenced the types of panels found in vehicles [Source: Weber].

The interior panels may be composed of a single piece of molded plastic, or several pieces of plastic. As other areas of automotive manufacturing have evolved, interior panels have from being made from pieces of metal, to thin pieces of cardboard, to molded plastics, fiberglass and wood. [Source: Partstrain]. Most modern interior car panels consist of molded plastic pieces with areas for storage and electronic features, such as power windows and door locks, integrated into the panel. Other functions and luxury features may also be housed inside the door panel.

As the price of cars goes up, the materials used for the interior panel also changes to accommodate the style and price of the vehicle. One manufacturer said that in recent years, consumers that purchase a $20,000 vehicle expect an interior that looks like a $30,000 vehicle [Source: Weber]. Wood is a popular type of interior panel that can be found in luxury vehicles -- although the entire panel is not typically constructed entirely of wood, it consists of sections of wood, as well as leather and other high-end fabrics and plastic.

In addition to luxury interior panels and plastic panels made for design and function, the auto manufacturing industry has increased production of interior panels that are more environmentally friendly. As the demand for vehicles with a low environmental impact has increased, interior car panels are being built with more recyclable materials [Source: Weber]. Some countries in Europe require auto manufacturers to build vehicles that are 85 percent recyclable, including elements of the interior door panels, and U,S. manufacturers are increasingly becoming more environmentally conscious with their materials as well [Source: Weber].

Let's go on to the next page to find out what types of technology are being used in interior car panel installation and how it's changing.

Interior Car Panel Installation Technology

As we mentioned earlier, interior car door panels in the past were installed completely by people in the past, but now, robots take on many aspects of the process. On some assembly lines, robots are used to fix interior door panels to the exterior door sections by applying a thin bead of adhesive to the exterior section and then compressing the interior section onto the exterior panel [Source: Assembly Magazine]. Operators load the door panels onto a track where they are then assembled by the robots.

Once the two parts are sealed, or clipped, together, some automotive manufacturing plants use robotic cameras to rotate around the interior car panel to ensure that all areas of the interior panel are lined up and sealed properly [Source: Assembly Magazine].The camera then uses LED strobe lights to take multiple pictures in several areas of the door.

If one of the pictures shows an area that is misaligned, the door is pulled off and fixed or replaced. Incorporating these robot cameras ensures that mistakes in the installation process are found and corrected quickly, which saves money on auto manufacturing costs [Source: Assembly Magazine]. It also saves money for the consumer by providing better quality products that require less maintenance.

Interior car panels are becoming more than just an aesthetic part of the door, which means additional installation steps in the auto manufacturing process. Some car companies, such as Ford, add impact-absorbing foam blocks between the inner door panels and the interior trim during the car panel installation process. These foam blocks are placed near the occupant's chest and hip areas to protect them during an impact [Source: Ford]. As safety regulations and consumer interests change, interior car panels and their installation processes continue to adapt to their requirements.

For lots more information about interior car panel installation, see the links on to the next page.

Related HowStuffWorks Articles


  • Assembly Magazine. Assembly in Action: Auto Manufacturer Uses Vision to Error-Proof Panels. Dec. 1, 2003. (Dec. 24, 2009).
  • Ford. Driver Survives High-Speed Yellowstone Bison Crash to Buy Fusion Again. (Dec. 29, 2009).
  • Partstrain. Honda Door Panel. (Dec. 26, 2009).
  • Weber, Austin. The Inside Story. Assembly Magazine. Jan. 31, 2007. (Dec 26, 2009).