Yesterday (Father's Day here in the US) I gave my 4 year old grandson his first m/c ride. He LOVED it. After riding about 15 minutes, grandma asked if he was ready to go home...he said "NOT YET" very emphatically.
Got a feeling he'll become pretty familiar with the back seat over the coming years.
Pix:
http://picasaweb.google.com/wingriders/KyleRide
Joe