True.
Here is the 'textbook' on DIY:
Build Your Own Electric Vehicle. Second Edition 2009 [first edition is pretty out of date]
And a Canadain book:
Zero-Carbon Car. Building the Car the Auto Industry Can't Get Right
This has much more on social, economic, and enviro considerations. Including the best discussion on the whole cycle of inputs into an EV or hybrid.
And there is a good detailed discussion of building one car. But it is a unique project, and he admitts the car he chose to convert is unusual [I think simply because he owned it already].
His argument is that the best low carbon choice is a hybrid that has a diesel generator burning bio-diesel. So that is the car he built.
I take an overall systems and longer term view towards the best low carbon choice. But even if you are looking purely for your least contribution to carbon right now; then for less hassle than the on board bio-deisel generator, you put in PVs or wind turbine for charging the batteries. Or just do the more straightforward work of a diesel vehicle to burn bio-diesel you produce.
Of course the hybrid has unlimited range. But that just assumes you need to fit into existing jump in and go notions of personal transportation. And so what if your EV cant do everything you need a vehicle for. Even a single person can have a modest second vehicle for the longer or extreme cold weather trips.
At any rate, I think Kemp's book is the best general discussion.