While driving you probably don’t even realize what’s lurking behind some of the interior panels, but there are all kinds of things back there from electronics to speakers.
Let’s start at the top with the headliner. It’s designed to not only look nice on the side facing you inside of the car, but it also keeps the interior quiet by stopping a lot of sounds from coming through the roof into the vehicle.
Luxury cars have a little more sound deadening panels up there and that leads to a quieter ride. The headliner also carries wiring that goes to things such as the dome light, antennas and other electronics that are located in the roof area.
Sunroofs are made up of glass, electric motors and tracks for the sunroof to slide back and forth. What might be surprising is the fact that sunroofs have gutters and drains for any water that might get into the sunroof assembly. These drains go down through the pillars of the vehicle and dump the water out onto the ground. If these drains get clogged, water can drip inside the vehicle sometimes even right onto your lap. That’s never a good thing.
On the side of your vehicle are trim panels that look simple enough, but many times what’s behind them is high tech. Airbags are often located along the roof line behind the trim panels and they protect you in a side impact crash by firing out and creating a barrier between you and the other vehicle.
Vehicle doors have a lot of parts inside as well, including speakers, power window motors, power lock actuators and other electronics like control modules for the power seats.
Seat belts are mounted in the center pillar on many vehicles and they have a spool assembly where the seat belt wraps up when it retracts. Some seat belts also have a pretensioner inside of them which fires when a collision happens. That pretensioner tightens up your seat belt in milli-seconds before your body moves forward in a crash. That helps restrain you and keep you safe.
There have always been a lot of electronics and wiring inside of vehicles, but automakers are putting so many gadgets on vehicles these days they are running out of room to put them. Because of that, they put some under the carpets and seats on interiors.
The downside of hiding electronics down low like that is when water gets inside, those electronic modules can be ruined when they get wet, costing you hundreds, if not thousands of dollars in repairs.