Some tanks/vehicles wont give the eye if u press "X" or examine.
This is for really burnt out stuff...most do work....
Try my fav - drive up to a broken vehicle with your tank/jeep/other and then click "X" and transfer all over...
Oh...clicking transfer all don't always work! Double click it - that usually does it...else nothing and it's a manual drag em over.
Nother tip if using the far easier vehicle to vehicle/crate method - if you are scared of trashing/crushing the e.g. crate, parallel move alongside it [next to it], then sloooowly rotate your e.g. tank towards the crate [stop n "X" as you progress] - soon it will show the inventories and you have the goodies.
I prefer to use the jeep as you scoot over bodies and gather like mad as they don't do that awful "squish-n-disappear" - then unload the jeep at my truck or tank ever so often.
A fav tip on collecting inventory...if you are not sure of time or crushing/blowing up crates then use infantry to drag all the contents onto the ground - at least the goodies remain for later - or split them up between vehicles [takes time i know]
But...then...unlike my early noob method of having my single preciousssss fully loaded tank getting brewed up from the infernal "single last shot from your destroyed enemy that is frakking potent and kills you too even though the gun or tank is blowing up]
...Must be Hero Heinz the flameproof gunner with ball bearings for...etc.
lol