Doesn't. Its filaments are in completely the wrong position to work with a lamp designed for any of the bigger bulbs. Also it puts out the wrong amount of light for the '65-'66 Dart application we're talking about here. Also, it would require brutalizing/hacking the '65-'66 Dart inner taillight socket to even fit.
(that "mini 1157" is not a legitimate bulb, it's something dreamed up by a squirrel to sell aftermarket toy lites to motorcyclists. Years ago I worked for the company where that squirrel had done so years before, and so I had a front row seat and speakerphone for the steady trickle of "Hey, my light melted/wires burned/lights don't work right" etc types of complaints that would come in).