Hey there !
I came from nowhere but have an awesome game to present to you: Warzone 2100
It's a RTS which came out in 2000, and has been open source since 2007.
You can build your own vehicules from top to bottom (chosing the chassis, propulsion and weapons (or systems). It's really complete for players who love tactics (defense, counter defense, radars, etc).
I've been enjoying that game since it exists and I can't have enough.
Feel free to try, it's free !
PS: I've been monitoring Inovae since the old forums, but never had the courage to register
You guys are amazing. I love reading your posts (most of them are too scientific though )