Radio Use and Creature Comforts
The peak current required by a powerful audio system can be substantial, but unless you are using your subwoofer as an alternative propulsion device (as some neighbors' teen-aged children must be doing), the average current draw isn't unmanageable. Not counting fancy displays and the lot, the power required to create reasonable audio levels isn't that great, and surely wouldn't have a significant impact on the AER. Now, running things with motors, like tape (what's that?) or CD drives, that will bump the consumption a bit.
It seems that we are already having to do without the heated seats, so don't take away the other power options - windows, door locks, etc. If you reduce the electric car to nothing more than a high-efficiency "go-kart", you will lose a good number of potential buyers (like my wife). Besides, it's not like you use the windows and locks continuously. While sitting in a parked Prius (ICE automatically switched off) while running the environmental control system (fan), I watched the battery charge status drop minute-by-minute. It's the continuous use of high-current devices (like motors) that will get you.