im havin trouble with the 'used car salesman' achievement in Halo 3?

[daniel]

i kno how its sposed to be done (destroy a vehicles with 3 enemies in it) but i swear ive destroyed a loaded prowler a gazillion times and no achievement, and destroying the turret on the phantoms isnt helping either!!

 

[emptyF]

The only time I got it was when I took down the whole Phantom.

 

[emptyF]

The only time I got it was when I took down the whole Phantom.

 

[FOR SPARTAN 117]

take a rocket launcher and destroy a vehicle with 3 enemies.(didnt help to much did i?)be sure they are 3