Rear Light Corrosion
Caterham rear lights always corrode on the inside as they cannot effectively be sealed. This is because they are trailer/caravan rear lights, but mounted upside down. As the drain holes are now at the top water gets in, especially if the car is used all year round. To prevent this, drill a small drain hole in the bottom of the lense in each 'compartment'. This lets the water drain out and prevents the corrosion.