The opening sequence, which is a simple montage of Lupin and Jigen driving around in their Fiat before setting up camp for the night just outside Cagliostro's border, set to the oddly somber song "Fire Treasure". It's such a stark contrast with everything that happens right before and after, yet sets the film's tone perfectly.
When Lupin and Jigen are being chased by ninjas in their car, they pile on the souped-up subcompact car and the rogues have to get them off. How do they do that? Simple, they maneuver near a wall, put the car into a side-wheelie and they literally scrape them off!
"So help me, Count, if you lay one slimy finger on Clarisse, your precious ring is gonna end up like this!" *fake ring explodes into confetti in the Count's hand*
The original Japanese dialogue and the dub as quoted above give different flavors of awesome: in the Japanese, Lupin speaks in a flippant tone, essentially flaunting and mocking the Count's power. The dub instead has him speaking in an incensed tone for an effective moment of O.O.C. Is Serious Business.
Lupin and Zenigata kick copious ass when circumstance brings them to work together, and it's no different here when the two bust out of the castle. None of the goons even manage to lay a hand on either of them until Lupin gets shot, but even then, Zenigata proves to be the decisive factor and ends up saving both Lupin and Fujiko using the damaged autogyro—and this was his first time flying one, to boot!
For that matter, Clarisse shows that she's made of some pretty stern stuff when she dives in to shield Lupin's body from more bullets. She doesn't lose her nerve for a moment as the rounds land all around her.
The entire climax of the film in and around the clock tower is both one for the animators and Lupin. After the terrific chase and fight amongst the gears, he manages to beat the Count by giving him exactly what he wants.
The moment when Lupin and his gang stop the Count's wedding. When the Count's men seemingly skewer him and then move on to do the same to the others, that is when Lupin pulls off his masterstroke and gets ahold of Clarisse and the rings when and where the Count least expected it. Clearly, underestimating Arsene Lupin III is suicide even when the Big Bad is at the height of his power.
Also, Fujiko beating up the Count's Elite Mooks when they try to stop her broadcast and Zenigata and the Japanese cops in riot gear barging in and trampling the Count's ninja. Then the royal guards show up... And the cops start beating them up, just as already did earlier in the movie.
Truth in Television: Japanese riot cops are just that good: they're chosen among the strongest recruits and extremely well trained in marching as a phalanx, using their shields to protect themselves and hitting the opponents, beat up their opponents with their nightsticks, and disperd rioters without using guns (that they usually don't carry anyway) even when faced with molotovs. No wonder the poor Cagliostro guards were beaten up so badly in spite of their superior numbers...