The third big feature we're focusing on during development of Arma 3 Helicopters is, of course, Firing from Vehicles. We are getting very close to having a version ready for Dev-Branch. Hopefully by the end of this week, you'll be able to try the feature for an initial batch of prepared vehicles (e.g. the MH-9 with benches and the offroad car)(http://dev.arma3.com/post/sitrep-00074)