He said the trolley was mostly built out of parts lying around at home.
Dunn said they were stoked with how it turned out.
He said he liked how the derby had allowed Xavier to form an idea and then follow through with making a final creation.
Xavier said he was excited, though a little nervous.
"I enjoyed watching it [the trolley] come together."
Another young trolley racer said it was fun at the beginning of the races because you went really fast.
Last year, 15 Rotorua Lakes High School students were helped to host the Amazing Place Race.
Feedback from the community was to have another event in 2018.
This year Mokoia Intermediate students were given the opportunity to be involved by hosting the trolley derby.
Ralph Mosen, programme director for Horizon Consultancy Ltd, had also worked with students from Rotokawa, Owhata and Mokoia Intermediate schools building trolleys for the event.