LEO: Please give me your cell phone so I can plug into my black box and download all your personal information from it.
Me: No thank you. I do not give you consent to search.
LEO: You know I can hold you here while we get a search warrant, right?
Me: Actually, no you can't. You cannot detain me longer than what is reasonable for a traffic stop for the purpose of obtaining a warrant and you have no probable cause. Is there anything else, officer? No? Have a nice day.
================================
Bottom line, politely refusing to consent to a search where the officer has probable cause is a nice way of telling him to get ****ed. And he cannot force you to give over your phone unless he already has a sworn warrant, which he'll never get without probable cause. Speeding or not signaling does not constitute probable cause.