As soon as you reach the end of the first motorcycle level, the pickup truck carrying a Donovan Mook that was harassing you crashes into a cargo truck. As a result, it loses a wheel and the said Donovan gets sent smashing into its back window head-first.
Similar one is when you have to smash your way through some walls and another Donovan mook try to run you over with a bulldozer. At the end of the level, there is a steel pillar that finally gets between you and the bulldozer. The bulldozer will crash into it and the impact sends a barrel rolling down from the above level, and knocking the mook out.