Ok, this is my first guide ever and far from perfect so please be merciful. There are 2 garages in each region (Michigan, Alaska and Taymyr. When u start game and complete tutorial, you'll unlock 1 garage in Michigan and 1 on Alaska. At this state, u can also quicktravel to Taymyr and unlock 3rd garage. Other garages are in second map of Michigan, Smithville Dam and third map of Alaska, White Valley. Those two garages are quite easy to find and should be no problem. However, final garage is much more difficult since u have to "build it" by completing several Contracts in Taymyr. I don't remember 100% certainty which contracts but I think there were at least 5 contracts, some of which were pretty difficult so don't attempt this until u are high-enough level so u have good trucks and mudtires. Offroad truck is recommended since u need to use Seismic Vibrator-module. Contract that finally unlocks/builds u a new garage is called "Hub Recovery, 2nd Stage". Before u can do this u have to complete several other contracts, many of which consist geological recearch which require Seismic Vibrator-module. While u do these contracts, they'll open second map for u, Quarry, and finally third map, Zimnegorsk which the final garage will be buld. Note: to unlock achievement u have to enter each garage. Hopefully this helps!