I thought about a similar project when i was doing my headlights...it was more of an extension of the fiberglass eyelids that were produced for our cars. Just overlay a thin layer of fiberglass over the stock lense...let it cure, then reinforce from the back. Then use the Hella 90mm which are a fully sealed and weather proof unit and you wouldn't even need the back of the housing. Create some brackets that mate the Hella high and low to the 3 mounting points on the car, as well as to a sealed turn signal unit (aftermarket LED would be perfect)...then figure out a way to secure the fiberglass front to the car... and that pretty much sums it up. The catch is that you would need to introduce a curved recessed area underneath where the projector sticks out from the fiberglass surface so that it flows around the projector lense...but that can be done after.
