My dad stopped his Renault (2.5litre turbo) Alpine in a country lane, and got out, and said "your turn". I think i was 15 or so. That was fun! Only drove it for about a mile, but it was fun!
My grandparents live on a private road in the middle of a golf course, and I would regulary sit on my dad's knee and steer my way to the main road when I was a nipper. I would also control the gear stick for him sometimes when we were driving about on normal roads (my mum let me do this too!). As I got older (12+), I would often drive the 1.5 miles of private road on my own with him sat next to me.