As said before, the best idea would be to use the feedback tracker. Don't be afraid to talk about an issue that they are actually working on, it is better to name it and be told that they got it on their list than to keep it for yourself and never get it fixed.
There are already quite a few tickets dealing with vehicles, vehicle features and movement, here are a few that are important to me:
http://feedback.arma3.com/view.php?id=4919 (vehicle movement)
http://feedback.arma3.com/view.php?id=10372 (unrealistic /useless smoke deployment)
http://feedback.arma3.com/view.php?id=9782 (missing features of RL counterpart)
http://feedback.arma3.com/view.php?id=5711 (the gearbox idea)