The body holds the car together in most lighter cars. This is called &quot;monocoque construction&quot;. You can&#x27;t just add the body. Body-on-frame construction is used for trucks and some larger cars, but there&#x27;s a weight penalty.<p>The trouble with in-wheel motors: unsprung weight.  Works great for big, slow vehicles like mining trucks.  For smaller vehicles, the motor weight has to come way down. There&#x27;s been some progress in this.