Sound insulation element for the firewall of a vehicle body and support element for a sound insulation element of this type

A sound insulation element for an end wall of a vehicle body arranged between passenger compartment and engine compartment, with

• a composite component comprising a plastic carrier layer and a sound-absorbing layer connected thereto,
• wherein the composite component has a front side facing the passenger compartment and formed by the outer surface of the plastic carrier layer, as viewed in its installed state, and
• a rear side which bears against the front wall and is formed by the outer side of the sound-absorbing layer facing away from the plastic carrier layer, and
• at least one first passage opening in the composite component,
• wherein the first passage opening comprises a carrier layer hole formed in the plastic carrier layer having a hole edge and a sound absorbing layer hole formed in the sound absorbing layer having a hole edge, and
• wherein at least one holding-down projection projects from the plastic carrier layer at the and/or offset to the hole edge of the carrier layer hole on the inner side of the plastic carrier layer facing away from the outer surface of the plastic carrier layer and thus facing the sound absorbing layer, which is embedded in the sound-absorbing material of the sound-absorbing layer and whose free ends facing away from the plastic carrier layer are substantially aligned with the outer side of the sound-absorbing layer facing away from the plastic carrier layer.