Racing vehicle (2-4)
I believe the answer is:
go-kart
'racing vehicle' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for go-kart that I've seen before include "Miniature racing car with skeleton body" , "Small racing vehicle (K, not C)" , "Lightweight racer" , "Small low motor vehicle used for racing" , "Small motor-racing vehicle" .)