A quick backstory: I cracked the left lens on my 2004 S80's factory installed xenon lights. I has been a virtual nightmare looking for a replacement glass or a reasonably priced assembly. Full story for anyone interested is here https://volvoforums.com/forum/showthread.php?p=218409 .

Anyway, since it turns out I can't just reflash the car's computer to recognize halogen lights, my only recourse was to buy an HID conversion kit that already has the same power draw (as to not make the car throw errors at me) and install it in a halogen headlight assembly.

Well, I forgot one minuscule, insignificant detail in my devious plan - does the halogen assembly have the same physical shape and the same mount as the xenon assembly?