Pathfinding
Vehicles will now be better at driving through narrow passages, they will be less likely to get stuck
Vehicles will now be less likely to enter a tight spot, thereby reducing the occurrences of on-the-spot pivots
Improved the way three point turns are executed
Improved the way vehicles respond to facing orders
If you remember before the Sep 9th patch all vehicles suffered from very bad pathing problems. For example, when you ordered the m3 to reveres, it would move forward 4m and then start reversing. In the kubel case this was causing it to behave very erratically and often end up getting destroyed before it could get out of trouble.
Now that pathing was fixed its high stats make it very op unit. For example, its fast acceleration (4.5) makes it hard to flank, it's small target size (10) makes it hard to hit, and it's high sight (50) awards it sufficient awareness to never get in trouble in the first place.
The last patch has fixed some problem, primarily excessive damage and suppression on the move, but it's still an op unit. If relic wants to fix this unit they need to add a 10 fuel cost, increase its target size to 15, and reduce it's acceleration to 2.5-3.
I think with those changes this unit will be closer to balanced.