Try your Mechanic roll (roll 1 die, trying to get a result less than or equal to your Mechanic skill). Each roll takes an hour of time. A successful roll repairs up to 5 hits of general damage to your car, or 1 damage box on a weapon. If you fail, you can quit and leave, or roll again until you succeed.
When you are through (or give up), mark off all the time you spent on repairs and tum to 342.