I barely remember it now, but when my oldest child was a preschooler, we started driving lessons. I remember something falling through in our schedule and suddenly having a few minutes to ourselves. Not enough time to go anywhere and get something done, too early for the next appointment, so what to do? We already were in a deserted parking lot with the baby asleep in the back. So I let my son climb onto my lap behind the wheel. Boy was it a thrill (it probably means more to this car seat generation than it would have years ago) to actually steer the car around the parking lot. Of course, I had control of the accelerator and brake pedal (and wheel if I wanted, back then I could still muscle him), so I had nothing to fear. It was so fun that we would look for more opportunities to let him "drive." Now my daughter is excited for turns to drive as well.
Eventually though, the boys got too big for my lap. This is a bit scarier, but we go to the only private parking lot we know of that is kind of "ours"--our church parking lot--when it is deserted.
One thing I like about doing this, is that at an age when it seems kids stop listening to you, all of a sudden, they are all ears. We go through it all from seat belts and mirrors to the fact that they have complete control of the gas pedal and brake. No radio allowed; focus is important. They particularly love the ceremonial handing off of the keys as we pass each other, walking around the car to trade seats. We start slow, and it's still a thrill for them. If anyone walks or drives into the parking lot, they stop and wait.
I like doing this with them for several reasons besides having their attention. One is that it doesn't take a lot of time or money. Another is that I can feel their excitement, and not often do my teenagers get excited to do something with me! Another reason is their confidence and mine.
My second child is turning 15 soon and wants to know when we can go driving again. He's taking drivers ed and hopes to get his permit on his birthday. When I take him driving now, he likes working on his parking. Each time he parks, we both open our car doors and report how far we are from the line.
Occasionally I hear the parent of a teenager express their angst at the prospect of their child driving. I've also heard the apprehension of a teenager at being behind the wheel. I hear stories of parents screaming while their child is driving. How safe is that? Figure out whether mom or dad has the best temperament and inclination for it, and take your child driving. It doesn't need to be often. They'll be thrilled, and when the time comes to let them on to the street, your nerves will thank you.