The inside lenses of exterior lights (headlights, brake lights, etc.) may fog temporarily if you have driven in the rain, or after the vehicle has been run through a car wash.
Dew condensation also may build up inside the lenses when there is a significant enough difference between the ambient and inside-lens temperatures (similar to vehicle windows fogging up in rainy conditions). These conditions are natural processes, not structural design problems in the exterior lights.
Lens design characteristics may result in moisture developing on the lens frame surfaces. This also is not a malfunction. However, if you see large amounts of water accumulation, or large water drops building up inside the lenses, have your vehicle inspected by a dealer.
Honda Civic Owners Manual. Modifications
Do not modify your vehicle in a manner that may affect its handling,
stability, or
reliability, or install non-genuine Honda parts or accessories that may have a
similar
effect.
Even minor modifications to vehicle systems can affect overall vehicle
performance.
Always make sure all equ ...