Yes it is Klown but it completely depends on what the cop is trying to do. Some may just ask you if they can search the car or not if it's really late at night and they do not have another call. In which case a police officer can completely design the question to get people like Vic. If you don't allow them and they don't have probable cause then they are allowed to have you pulled over for a certain amount of time to wait for a K-9 unit.

In what I talked about when the officers asked me if they can search my car, all the cases were late at night. They made contact for what I can assume was to see if I had been drinking or under the influence. Because I wasn't and I cooperated with them, they didn't even bother to search my car even though I told them it was ok. And of course I am talking about actually being in my car, all cops will snoop around when they are at the window. This is why I believe the best approach to talking with officers is situational though. It is good to know your rights but playing the punk kid that doesn't want to cooperate can land you in trouble also.