The headlamp covers get tarnished inside and out. It is possible to make a significant improvement by using an abrasive polish, such as Mothers Plastic Polish, or T-Cut. The outside is easy to clean but to clean the inside requires the lamp to be stripped down and rebuilt which this means seperating the two halves of the light. This is impossible to do without softening the glue that holds the lamp halves together. The following was written by Craig Oakley after following a similar guide for the Toyota Supra.
How to clean a Toyota Sera headlamp (Oakley Method)
(Click any thumbnail for a larger picture.)
– Remove headlights from car.
– Turn on oven to 150C
– Remove all bulbs and cowlings, all 5 metal clips, the metal attach bracket (held on with 2 screws) and the screw near the indicator light.
– Place headlamp in oven for 5 minutes.
– Use flat head screwdriver to lever the headlamp open from the headlight end (not indicator end). If glue gets too hard or the unit cools too much, re-heat in oven for up to another 5 minutes to soften glue.
– Once front and back separated, remove the screw from the interior near the headlamp end and remove the inner lamp assembly.
– Clean the plastic headlamp cover inside and out with something like t-cut.
– Reassemble the headlamp interior.
– Place both back and front half of assembly in the oven for 5 minutes to re-soften the glue.
– Push both front and back halves together and use the 5 clips to re-lock the halves together.
– Re-insert the indicator end screw.
– Replace all bulbs, cowling and re-attach metal bracket.
– Reinstall clean headlamp into car.
This is all fairly simple. If I can do it anyone can.
Note: www.toyotasera.co.uk does not take any responsibility for problems encountered when following this guide.