All Fall Down- Defeat a fully-upgraded Kyklops
Watch its movements carefully! When it starts to attack, it will lower it's shield for half a second. Practice your timing for chucking a large car at it when he does this. When you hit him right, he'll go down. Unleash a combo before it and its shield get up.
I missed the Gold by 0.65 of a second, but this another method that I believe should work and that I just got unlucky. (Hey, after finally getting "Struck Out", I consider the game lucky to still be in one piece.)
Immediately find a car and equip it as gauntlets. (If this takes longer than 10 seconds, restart.) Then stand directly in front of the Kyklops. The Kyklops will smash down and if done properly, it will activate a button-mashing mini-game in which you push the Kyklops over. When the Kyklops stands up it will twist its arms at which point you need to back off just a little. The Kyklops will fall forward, leaving its eye exposed. I attacked with X, X, X for the first combo and the second combo X, X, charged Y. Repeat all steps until victory.
Note: When I tried X, X, charged Y on the first combo, the Kyklops immediately stood up. It seems that both a certain amount of damage and an implicit time limit are at work here.