One or two points struck me:
First one is the batteries take up a great deal of space - I hadn't fully appreciated that. Taking out the back seat is a lot - I'm not sure there's much point in a 2-seater Volvo estate
No motor to run the power steering
No hot water for a heater
No vacuum for the brake servo
There's a Youtube article on a classic short wheelbase Landrover conversion, and the electric motor was so small they fitted all the batteries where the old engine had been.
Acceleration was incredible - far too quick for safe ordinary use, and much faster than ordinary IC cars. He usually left it in top gear. I can't remember what its range was, but I think it was greater than the 40 miles of the Volvo conversion.
Just a thought that if you went for direct drive and no gearbox you could fit the motor under the floor near the back axle and free up the whole engine/gearbox space for batteries. (Or turn the axle back to front and use the space under the boot floor)
It's a fascinating subject anyway, and I'm sure there will be design improvements over the next 10 years. Or else electric cars will be superceded by something else anyway.