These parts fail invisibly and then loudly. The foam crumbles, the insulation falls onto the pedals or the transmission tunnel, and a water leak shows up as a damp carpet rather than as a visible defect. Replacing a seal is often part of a leak repair, because the old one will not seal again once it has been removed.
Order by position and by shape rather than by the name of the material. A dash insulator is moulded to the contour of the panel and will not interchange between body styles. Where the insulator doubles as a heat shield, confirm the model and engine, since the exhaust routing decides the shape.
