need help with props (cones etc..)

hi guys,

Is there a way to remove the ability to control props like cones?
I created a small driving course with a bunch of cones but its annoying having to cycle through them all to reach an different car

 

You have to save the prop on the map as an object (e.g. like buildings are objects). Unfortunately I don't know how to do it so that's it with my help.

 

ok thanks