This is not my own work, it's Malidictus' mod CarLogistics (https://mods.factorio.com/mod/CarLogistics), but changed to version 2.1. (Feel free to contact me using one of the media listed on my website https://kruemmelspalter.org to take it down if you update your mod to 2.1 etc.)

Enables the logistics grid for the Car when the Logistic System technology is researched. This gives the Car 20 logistics trash slots, same as the Tank and Spidertron, enabling it to interface with roboports. As a bonus, this also enables Remote Drive for the Car.

I literally changed two settings:

local car = data.raw["car"]["car"]
car.trash_inventory_size = 20
car.allow_remote_driving = true

If you want anything more sophisticated, let me know.