Hi All: The automatic headlight dimmer (an option of dubious value, in my humble opinion!) was offered on the Chrysler brand in 1959 and 1960 only. It continued to be available on the Imperial thru 1963. I do not remember how it attached to my 300F I/P, as it has been too many years since I took it apart. Sorry I can't help on that part of the question. 300ly, Gil [Non-text portions of this message have been removed]