Last night I had an LD cuz I was drifting in and out of sleep, and I one time when I drifted out, I decided that I was going to become lucid when I drifted back in. It worked, and the next time I did it, I was actually able "carry" my consiousness back into the dream. I kept switching locations, but it worked. I was kinda cool. this might be good for a car, cuz whenever I sleep in a car, I do pretty much just what I described. (without the LD, though.)