trial drive private purchase … if what happens?

so since I want to get rid of my kfz and certainly soon someone also wants to make a test drive I have no question what is it then if the oda drives the other somewhere so? I can happen my imma times what aba what looks like with the vers. out? would then pay my kfz liability (which means I get higher graded) oda nä hausrat vom ander? (if any available) maybe give there special regulations because I also specified that apart from me nobody else is driving the car okay thank you already greeting soul-was