We need concrete pads for GVs to tower out at near their spawns.
As it is, "yes", you can motor in, fight, and then motor out and if your far enough away from the enemy you can tower with your kills. But lest be realistic here. In a fluid, heavy fight, with GVs spawning and on the offensive, its very difficult to run a GV, most of all a damaged one, far enough away from the enemy to spawn successfully.
Add to that with the IL-2s, and Jabos, the advantage is with the defenders to begin with, "as it should be", and successful GV attacks on enemy bases are made even more difficult.
Picture this. You spawn out a Tiger or Sherman, head towards the enemy, get your action in, and with all the airplanes swirling around how easy is it to tower out successfully and not lose your perks/kills? Putting concrete pads near the spawn would reward honest GV'ers and reinvigorate the ground war by not, almost automatically, penalizing tankers with a perk loss for offensive action. That and your really skilled tank guys, the ones who care about their score, would get more involved in armor offensives and kick the ground war into higher gear.
Or in some way make it easier for GVs to tower, cut the distance amount needed or something. Even if your in a M-3 to drop supplies the reality of the current situation is your going to be penalized as a kill unless you spend all that time to drive away, hopeing theres no enemy close enough to ruin your tower.
The IL-2, or possibly a Stuka-G OTW, is a good thing but we need to throw the armor guys a bone too. Theres no reason guys should avoid perked tanks cause the rules make is so hard to successfully tower after a spawn/offensive action. Thats my take anyways.