I agree with moraine, the clear film trick sounds great.
I drive 20 miles through winding, narrow, paved, farm to market roads, just to get to the highway. In the winter I do all 40 miles of this in the dark, dodging deer and escaped livestock.
I put a set of the Hellas on my 240D ten years ago. Just after that was the Red River flood of '90. I had to ford high water a few times and did discover one of the lights was flooded until it was too late, the silver was ruined. If you use them, seal them good, even though you probably don't live on the Red River.
Several years back another one got broken (I should have used moraines clear film trick). Aftwer that I bought a pair of Sylvania XtraVision halogen sealed beams. They are about 85or 90% as bright as the Hellas. Just recently I bought a parts car for the engine. The parts car had a set of Euro lights complete with the dash mounted elevation adjuster. These are the way to go if your budget can stand the $400.
'84 Euro 240D, 516K miles
'88 300E 5 Speed
'81 300D Daughter's Car
Over 800,000 miles in