Mesh importing
Make a directory in your desired asset pack.
Let's call it PoliceCar
for simplicity.
Make directory inside that directory PoliceCar/Art
and import your meshes to it.
Makse sure that your meshes have correct collsion as well. In most cases you can use the generate convex collsion tool (with high percision and hull count).
Make directory inside that directory PoliceCar/Blueprints
Right click and select the Create Vehicle
Select the base class that matches your vehicle the most
1.Name your vehicle, no spaces no symobls and keep it short like PoliceCar
( this is not visual name of the vehicle and it will be used purely for file names)
2. Select your mesh
3. press create
Base is ready
Now your vehicle is created. You can start by positioning of axles doors and other components. and filling the data for doors and other components. To see how to setup each component please visit the components section