Import the car material into AE, and right-click the material to create a new composition.
Press the G key to draw a mask along the car body, and then press the M key to expand the mask option (I drew it casually, of course, you should draw it more carefully).
Create a new solid color (solid layer), which we call "particle"
When the new building is completed, it looks like this.
To add particle effects to this solid layer, you have to look up and learn how to adjust the particles to what you want. This thing is simple and complicated.
Click the Mask Path of the material layer, press Ctrl+C to copy, then click the particle layer, press P to call out the location, click the location, and press Ctrl+V to paste.
When finished, click the space preview and you will see the particles walking along the car body.
Hope to adopt.