Your Garage - The Tool Cabinets & Repair Bench
Exploring Your Garage - Car Mechanic Simulator 2015
The repair bench is the first bench to the left of the big doors. You can use this to attempt to repair many parts. This process can be improved by upgrading your repair skill, but the odds of success are really out of whack. Keep in mind that many parts require several successful repair attempts to bring them to 100%. You should also know that if you fail a repair attempt the part will be damaged and you won't be able to try to repair that part again.
Tool boxes are scattered around the garage; it is by interacting with these that you can purchase many of the upgrades for your garage. For more information, see Tools & Updgrades.
Keep in mind that you can click on the big garage doors at any time to go to The Auctions Center or the Old Factory Test Track (test drive).