How do you handle a stopped vehicle?

[CashCrop]

Can TX comment on this one about the searches? I think things may be different in the ole lone star, every stop I've had where the LEOs asked for consent to search went something like this:

Officer:Where are you headed tonight?

ME: Uhhhh, my friends house (I was a teen)

Officer: Anything in the vehicle I should know about?

ME: Uhhhh, I guess not

Officer: Is it ok if I take a look in the vehicle?

Now this is while the officer HAS MY DL AND INSURANCE, and he has not stated ANYTHING about whether or not I'm free to go, being detained, etc...

I am very confused on the consent thing. Does the officer have to complete the stop, issue tickets before asking for consent to search? Twice I've been asked and it was always during the probing questions phase before the officer stops back to his/her car.

And what about this free to leave stuff? Can I ask an officer as soon as he stops if I am free to go? Is it true I can leave my car on the side of the road anytime I want?

"4) Determine if You Can Leave
You have the right to terminate an encounter with a police officer unless you are being detained under police custody or have been arrested. The general rule is that you don't have to answer any questions that the police ask you. This rule comes from the Fifth Amendment to the U.S. Constitution, which protects you against self-incrimination. If you cannot tell if you are allowed to leave, say to the officer, “I have to be on my way. Am I free to go?”

If the officer says “Yes,” tell him to have a nice day, and leave immediately. If the officer’s answer is ambiguous, or if he asks you another unrelated question, persist by asking “am I being detained, or can I go now?” If the officer says “No,” you are being detained, and you may be placed under arrest. If this is the case, reassert your rights as outlined above, and follow Rules #5 and #6."

When do I know I am being detained?

Again, I think Texas law differs here, but if anyone can clear this up for me, I would most thankful.