My oldest son and I watched power wheels racing at the last New York Maker Faire from the moment it started until the trophy was awarded. With so many amazing things to do and see at Maker Faire, this is a surprisingly long time to stand in one place, and a testament to how much my kids and I loved it. When we got home, both of my boys built a race track that mimicked the one in NY and raced their matchbox cars around it for hours, naming each car after the cars in the power wheels race. This went on for weeks.
It was enough to convince me that it was time to put some extra power in our own power wheels car. I found a scooter motor on Craigslist, welding some bike sprockets to things, and installed a new drive shaft. Those hard plastic wheels have terrible traction, so I upgraded to rubber. Even at half the rated voltage, my 3 year old flys on this thing.