This is more or less a repeat of my victorious argument from a discussion of same some moons back:
It's simple common knowledge that round headlights are better. A lens gains its greatest diffraction at the outer edges, which the square headlight cuts away. The peripheral low-intensity light gained by this can illuminate a tree or rock or pedestrian that the square headlights would miss. Eyeballs, camera lenses, telescopes, all are round. High power searchlights, satellite sending dishes, fiber-optic cabling... all round.
Round is superior to square in structure. Squares are subject to greater stresses at their joints and must be gusseted to make them maintain rigidity. The ultimate goal of gusseting is to add more angles to a square... in essence, to make it round. The strength of roundness can be seen in the grandest of structures, characterized by the rounded domes and sweeping arches of classical architecture. While it is true that arches rely upon trapezoidal blocks for construction, this is more a matter of man's inperfection than of any implicit lack of strength in the circle.
Religion and folklore, indeed the nature of the universe itself has long acclaimed the virtues of roundness. The yin-yang... "the Circle of Life"... "It is he that sitteth upon the circle of the earth (Isaiah 40:22)". The structure of atoms, the very building blocks of all that exists, is a round nucleus within a round electron haze. Celestial bodies inscribe a circular path through the cosmos. Simultaneously, it has foretold the fallacy of the square... the Four Horsemen of the Apocalypse correspond to the four corners, or four sides represented in this most evil of geometrics. Taking the "square root" of many whole numbers leads to an irrational, or incomprehensible digit... to make this digit comprehensible, it must be "rounded" to the nearest approximation.
All this makes CJs better than TJs which are better than YJs. The deciding factor here is the turn signals. YJs have all square lights all around... inferior. TJs have the round headlights, but square turn signals... better, but still inferior. CJs have the obviously superior round turn signals in addition to the obviously superior round headlight, making them the best combination of all. Very early CJs had even more round lights, making them the ultimate expression of nighttime fortitude.
Additionally, if you're adding auxiliary lights, wouldn't square Hella/KC/PIAA's just look gay?
And the final blow was Janet Reno = square. Round wins.
Sometimes you eat the bear, sometimes the bear eats you