This may not be the correct forum: I have an '84 300SD and the lens of the left tail light is badly grimed with Diesel goo. To the point that the passive reflectors are about 95% blacked out. What is the method to get the left-side lamps as clean as the right? Nurse Diesel says, "Danke!"

Try using a smooth handcleaner such as "Goop" or "Stalube". Smear it on, let it sit for 10 minutes, work it into all the spots with a paint brush and rinse well with water from a hose.