I wonder if you could just make a mold and then find a plastic place to just make a clear plastic of the mold.
Of course, I have no idea how the lense is currently attached to the taillights. If it's glue that's probably easier then tabs, but then removing them without breaking anything might be hard
2009 128i Coupe Crimson Red
MODS: -Injen Intake-Magnaflow Exhaust-Carbon Fiber Spoiler - Carbon Fiber Grilles - OZ Ultraleggeras - CF Mirrors