using a buggy chassis as a heatsink

had a weird thought that came into my mind the other day
not sure if this is the right place to put this kind of thing
since the motor sits so close to the chassis in most buggy/truggy conversions could you perhaps make a wrap around heatsink which bolts to the chassis some how and makes contact with the metal on the chassis?
if it had a large enough contact area would it be effective?

probably a stupid idea but i thought i may as well see what you guys thought?