AM radio antennae of the ferrite coil or rod variety are tiny and have been in widespread use for over a century. http://www.hard-core-dx.com/nordicdx/antenna/

AM radio antennae of the ferrite coil or rod variety are tiny and have been in widespread use for over a century. http://www.hard-core-dx.com/nordicdx/antenna/loop/amloop.html http://www.hard-core-dx.com/nordicdx/antenna/loop/amloop.htm... If locating it within the electric vehicle's superstructure is not suitable to the manufacturer it is not difficult to put one in a stubby sharkfin roof mounting as is done with GPS, mobile phone, and satellite radio antennae.