sorry but your wrong, a cop cant search your or your property without a warrent, they may be able to get a dog but a dog cant be released into your car, it can just bark at your car so they have a lil evidence to get a warrent, but theres no way a cop is going to hold you just because you refuse to have him search your car, just be like sorry buddy in kinda a hurry here, or I got tapes in here I dont want you to see haha.
on cops they have reasons to want to search car; driving erratic, car smells of drugs, they can see illegal stuff from outside car, someone had called them in to get you, ( for example , I was smoking pot outside of a school, a cop pulled up and searched me, I asked him if he is aloud to search me and he said he is aloud because someone from an apartment building called him and gave him my description and that i was smoking and that was his only evidence to be able to search me, If noone had called him and he just decided to pull over to see what was up he has no legal authority to search me, and if he did I could get him in trouble even if he found something on me.