I was driving through Texas about 5 years ago with a friend; my friend in his car, and me in mine. We were on the interstate, he was in front of me, and he got pulled over for speeding. So I just pulled over too so I could wait.

State troopers did a quick search of his car, which they said was standard procedure for EVERY stop they have to make. It was just like looking inside the car, and a quick look in the trunk, nothing had to be taken out or searched through. He had nothing illegal and was nice to them, so they let him off with a warning. I'd reckon they have that law so they can always check the trunks for people-smuggling, and running huge amounts of drugs across borders.

I haven't checked up on that to know if what they were saying was the truth or not, but yeah don't ever trust a cop. They only pretend to be your friend so that you'll waive your rights and give away your best kept secrets...

So, check up on the laws for city/county/state traffic stop procedures. Ya never know when they've taken a little bit more of your freedom away.

Other than that, just simply say "I do not consent to a search." Say nothing more about it. Short simple answers are best.