So, as a Silent Hunter fan it is quiet surprising that I asbolutely liked this game, but hell, I did. SpinTires is absolutely awesome. Check it's modding website
http://www.worldofmods.com/spin-tires/ and watch it's official trailer on youtube to get the feeling of the game. Spin Tires has to offer you the most realistic and sophisticated physics engine to simulate vehicle's behavior perfectly. You'll see huge military trucks getting drown here, duh.