I am looking for hyperbolic word or phrase for the case when you are using very complex or capable thing in such a way that even though the purpose is served, it was not used in the optimal way thus the optimal result was also not achieved. Like when someone is using a car as a hand cart or something.
EDIT: The message I want to convey is "you can do the same task in better way using the tool" and not "you can do the same task using a simpler tool".
While "A sledgehammer to crack a nut" represents the later idea, I am looking an expression for the former.