OK, maybe this can help someone. I lost my keys for my 190e. got replacement from the vin number and the key wouldn't open the trunk lock. Anyway, after visiting numerous locksmiths, I went to the salvage yard bought a back light, knocked out mt back light, and opened the trunk. Bingo! Less than ten mins, no drilling the lock out and the backlight was cheap, now I'm off the locksmith.

Hope this helps