Okay yall, this is something I am very familiar with. 1st off if a cop asks to search you or your vehicle and you grant them permission. They can search. If they find something (i.e. drugs, guns, or other contraband) You can and mostly will be arrested and charged (yes it is admissible in court). However, you can terminate the search at anytime. (Unless they have already found your drug stash, in that case your screwed) If your stopped and Arrested for example a DUI/DWI. The Officer is going to search you incident to Arrest and the lunge area of your vehicle (the area with in your reach) In some states the trunk and other locked areas you neead a warrant, probable cause or the permission of the driver to get into. even if you are arrested. However in Arizona they have gotten around this because the Officer has to inventory the cars property. So in the course of an inventory of a vehicle and something illegal is found it would be seized as evidence.
Bottom line here is if you are stopped for a moving violation (ie speeding, equipment violation) and the officer asks to search your car you can tell them NO! The officer also has the legal authority to get you and your passengers out of the vehicle if for no other reason because they want to.
If a Officer asks you to get out of your vehicle they may want to pat you down for weapons. There is a legal difference between "Pat Downs" and "Searches". A Pat down is a pat down of the outer clothing only. They wouldn't be able to open your jacket or coat or reach into your pockets. A Search is a lot more invasive and the officer must have Probable Cause, Incident to Arrest, Warrant or your permission, they can and will open jackets and get into your pockets(At least they should).
People do some research on your own and know your Constitutional Rights.
This post is by no means the Gospel on Searches. There are differences with in the States and Agencies have policies in place that could differ as well.
DO NOT GET OUT OF YOUR VEHICLE UNLESS THE OFFICER ASKS/TELLS YOU TO DO SO!!!
I know traffic stops are nerve racking events but don't make it worse by putting the officer on edge by getting out of your vehicle on your own.
Another tip for when your pulled over, Tell the person your on the phone with you will call them back(Get Off the Damn Phone) Turn your radio off (The officer doesn't went to talk/yell over your tunes). At night still do the above things and add turning on your interior lights.
I can't think of anything else off the top of my head, if you have questions about this post. Post me a Message or send me an E-mail. I will do the very best I can to answer your questions. I hope I didn't bore you to death with this. Take care.
Mick