Toolkits are an item in State of Decay 2. Toolkits, and their upgraded counterpart, the advanced toolkit, are the only method of repairing vehicles in the game.
Location[]
They can be found in workshops, garages, auto shops, and sheds throughout the game. They can also be crafted with parts at a level 2 Workshop facility, as long as you have a survivor with the Mechanics quirk skill. They can also be obtained from a parts trader or wandering trader for a relatively low cost, so this can be an easier option than looting or using parts to craft them.
Repairing[]
Toolkits can be used to repair vehicles by about 50HP, so it may require multiple toolkits to repair a vehicle back to mint condition. Advanced toolkits, however, can repair a vehicle to mint from any damage level, and the repair action is almost instant.
Strategies[]
It is recommended to only kill zombies, if you have to, with the back of your vehicle, as there is no vehicle damage taken when the back is hit, conserving toolkits and keeping your vehicle safe. It is also recommended to keep a toolkit in the trunk at all times, along with a gas can, to avoid being stranded if your vehicle is destroyed.