I feel the issue with vehicles is more down to the classes, and lack of variety with anti vehicle weapons / gadgets.
If there was a rocket launcher that could lock on to land vehicles without soflam, and a separate dumb fire anti air rocket launcher with a higher velocity and proximity trigger this would make it quite a bit easier to get vehicles. It would also be good to have a rocket launcher that would follow crosshair like the TOW.
Similarly if there were a few more options for engineer gadget combinations (ie a specialist with a repair tool, or AT mines as their specialist gadget) then there would be more defensive anti tank options. Currently I feel vehicles get ripped apart if they sit in a hotly contested area because a lot of people have recoiless rocket launchers. However if they are moving around they can dominate.
Currently the issue is -
1. Hard to kill heli pilots on certain maps - mainly ones with rooftop capture points when the heli can duck and weave away quickly continuously, and it takes too long to get a lock.
You can get a lucky recoiless rocket shot but this would be a lot easier if there was a dedicated dumb fire anti air rocket launcher.
2. Land vehicles if they keep their distance and move enough to avoid recoiless rocket shots. This would be easy to deal with if there was a lock on rocket launcher (that didn't need soflam) or mines were more common place. A lock on / crosshair following rocket launcher would need a lot of tweaking to get the balance right.