In which part of a vehicle is foam filler predominantly used?

Foam filler is predominantly used in the structural pillar and rockers of a vehicle due to its properties that enhance structural integrity and sound insulation. In areas such as pillars and rockers, foam can help absorb energy during a collision, contributing to the overall crashworthiness of the vehicle. The use of foam filler in these structural components also aids in reducing vibrations and noise, providing a more comfortable ride.

In contrast, the other areas mentioned, like non-structural sheet metal, doors, and fenders, may utilize foam for different purposes but not to the same extent as in structural pillars and rockers. These parts might rely more on metal reinforcement or offsetting designs for strength, while foam utilizes its unique characteristics in the structural areas to bolster safety and comfort features in the vehicle.