Crossout

Crossout is a post-apocalyptic MMO-action game for PC and consoles. Described as a crafting and combat MMO, the game allows players to construct their own post-apocalyptic vehicles to be used in PvP engagements with real players and PvE missions involving AI-participants. (wikipedia)

CROSSOUT, the post-apocalyptic MMO Action game! Craft your unique battle machines from a myriad interchangeable parts, ride them directly into combat and destroy your enemies in explosive online battles!
Key Features:

Unique vehicles, crafted by players using a wide range of available parts: from nimble buggies to heavily tracked off-road vehicles and even combat walkers.
Complete freedom of creativity and thousands of possible combinations: Create vehicles of any shape using a wide range of parts, with a wide variety of armour and weapons to help support your arsenal.
Advanced damage model: destroy any part of an enemy vehicle and it will affect the machine's performance immediately.
A huge arsenal of weapons: From chainsaws to power-drills, machine guns to rocket launchers, and a wide range of variety including flying drones and stealth generators.
Your own workshop: create new and advanced parts, and auction them at the in-game marketplace.
Trading options between players: every piece that you have gathered in battle can be sold to other players.
Choose your own battle strategy: Apart from victory, the only thing that matters is your Survival!
(official site)

Now open beta test.