Sorted from highest to lowest priority.

1. Allow crafting your own vehicles
   
2. Armor plates for vehicles

With mechanics level 7, you will be able to "remove" the engines of vehicles.
This will set their engine's condition to 0%, and you will receive an engine item.
The item is 20kg and has HP and Quality properties.
You will be able to install the engine in any vehicle with 0% engine condition.
The new vehicle will then have the engine's properties.

Minor problems
The game will reset the vehicle's engine to default if you use cheats to repair the vehicle, thus deleting the new engine.

Reloading the save also resets the vehicle's engine to default, but the mod will recover the stats as soon as you enter the vehicle again.

You will be able to repair any vehicle wrecks so long as they aren't burnt.
Below is a list containing all the requirements for it:

• Mechanics level 5
  
• Metalworking level 3
  
• Electric level 1
  
• 10 Engine parts, scrap metal, and scrap electronics
  
• 5 Metal sheets
  
• A welder mask
  
• A propane torch

You will be able to take this profession when creating new characters.
The auto engineer has good experience with mechanics, metalworking and electrics, and is capable of removing hotwires from vehicles. They can also reverse engineer vehicles on the go.

If you take the "Auto engineer" profession or read the "Vehicle Tricks" magazine, you will be able to remove the hotwiring of any vehicle. It works on the first try.