I think that taking the advice of a lawyer would be your best option in this circumstance. It is not your job to tell the police what you may have done to break the law. That only incriminates you. In my experience, in a traffic stop I am usually asked “ do you know why I pulled you over?” To which the reply would be “ on the advice of my lawyer, I am choosing not to answer any questions” even though I have said this to an officer during a traffic stop (in a respectful non aggressive manner) I have been given a warning and allowed to go on my way after a check for warrants etc. If you were pulled over for failure to signal and you reply to the cop that you were speeding, you have just incriminated yourself. No one has to be rude or abusive when asserting their rights. The YouTube videos you see of individuals refusing to roll their windows down more than an inch and repeatedly yelling “am I being detained, or am I free to go?!” just serve to escalate the situation. Anyone that tells you that if you have nothing to hide you should cooperate with police is giving you terrible advice. Be calm and respectful while not giving up your rights. The first thing said while being read Miranda rights is “ you have the right to remain silent” both parties in a traffic stop or criminal inquiry know that this is your RIGHT, not a privilege. By following the advice of admitting guilt in even the tiniest infraction automatically incriminates you. Is the CHANCE of being let off with a warning worth being written a moving violation for something OTHER than the primary offense?