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Rear lid
3.4.3 Cavity preservation
Unprotected cavities on the body are also potential starting points for partial corrosion. Corrosion can start there as a result of wet dirt from the street
sticking to the body or because of changing temperatures and the subsequent build-up of condensation (liquid deposits).
The cavities are therefore preserved with cavity protection wax both in series production and for repair work.
NOTE:
The lower parts of doors from the spare parts range must also be preserved with cavity protection wax.
3.4.3.1 Porsche 924 cavity preservation
This is a source reference. Confirm exact model applicability in the original material.