It is possible, but not with 2 car objects. If you try to do something like car in front car stop car and move other car, GDevelop won’t know which car object you are referencing for each action.
I would look at adding an extra object, like a small square. Place an instance of this object in front of very car, and link it to each car it is in front of.
Then remove all of these little squares that don’t collide with a car. You will be left with the little squares that are in collision with a car object.
You can now go through each of the little square objects, and perform whatever action on the car the car linked to it.