I peddled my son's KMX Kart recently as he had outgrown it and, since I had already bought him an adults version to replace it, I thought he was happy. However, he's clearly not the train set sort of person and whilst we had two karts he had enjoyed racing me, both of us pedaling around our quiet close. He stated we needed another bike and also managed to convince my wife :-)
So I went on a quest to find another adult Kart and was lucky to procure a really good, hardly used model.
N=19 again :-)