Can someone explain to me how the headlamps go back together? It's 2 weeks since I took it apart and now I've forgotten. I have the headlamp unit, a round black plastic thing and the new bulb.
Does the bulb go in first or the black thing? Does it matter which way around the bulb goes? Should I end up with the socket straight side up or curved side up? Does the black thing somehow hold in the bulb, and if so, how? I'm not about to remove the other headlamp and break all the adjusters to find out.

Thanks for any assistance.

David ('87 Wolfsburg)