I discovered a unique option of killing two at once in some cases.
Just target the object near them, like in the - do the most damage campaigns.
Just thought I'd throw that up for fun, being we Luv to just shoot the chit out of everything.
No idea if these options are in the higher levels as most of you are, but give it a tour.
https://farm6.staticflickr.com/5347/17871217835_e8733a4e89_z_d.jpg
Over by the rear of semi was a crate - taking it out, took out the high end shooter behind the semi.
Same as the car & truck strike took out those dudes.
There's other objects to the right of view.