Don't worry to much. Think about this, when someone race's their six million dollar 275LM in an historic race, oil is collected all over the car from other competitors.

Wash polish and wax, rubber protectant, and lots of window cleaner to rid of any film. Not sure on what exactly is wrong with your lights but you can disassemble and clean.

Any oil that drips into a hidden recess is probably a good thing, acts as an anti-corrosive. And you know that carnuba wax uses petroleum distillates to soften the original form carnuba.