What are the two key elements that must be present that trigger the requirement of police to give Miranda Warnings?

Hello,

 

I am having trouble answering these two questions. Can you please help?

 

Thank you!

 

1.     What are the two key elements that must be present that trigger the requirement of police to give Miranda Warnings?

2.     Police officers who have probable cause to search an automobile need not obtain a search warrant before conducting their search. What is this rule called? Why does it exist?