But now what?

First off, let me put in a little background. My dreamsign happens to be driving a car and having it be dangerously unresponsive, or having to steer a car from the backseat, or being in a car with no driver. I've had several dreams now in which I've gained a certain amount of lucidity by entering these situations.

But, recently, I had a dream in which I was in the backseat of a speeding car with no driver, and I clearly told myself "Wait, this is my dreamsign. I'm probably dreaming!" What disturbed me was that I then thought "Well, this seems way too real, so I better not take any chances. I had the perfect oppurtunity to become lucid, and then I go and blow it.

Does anyone have any tips on how to overcome my problem and more fully utilize my dreamsign?