They look like they were crimped by something that was hot and melted the plastic edges together.A corrugated look .It is the same with the tail lights as I had them off to

nly one bolt holds them in place!
Oven....I'm either not that brave or crazy enough plus they are way too expensive to play with in an oven and the only ones I have. If I get an extra set from a junkyard or Ebay someday,maybe. If I had an extra set I would probably send them off to Lightwerkz for a HID retrofit with S2K or TSX projector lens .I've seen his work and this dude is truely a headlight wizard.