This is what the factory uses to seal the headlamp

[TripleJackInGA]

As some of you know, I work for Hella here in the US, and in Mexico, Hella makes the headlamps and tail-lamps for the PT.
I e-mailed a contact at Hella-Mexico and asked him what is used to seal the headlamps from the factory, since many of you have chosen to remove the clear lens to be able to paint the chrome bezel inside the lamp.
I got a message back that what they use is called 'Butyl Hot Melt K292'.
I called the local Auto Refinishers Supply and they did not know of it, but he offered a couple of options I'll check into in the near future.it would seem that the 'Butyl Hot Melt K292' is something that needs to be applied with a hot gun of some sort.

I'll keep digging.