Step 2: Remove Anything Gasoline Related. Build Your Own Electric Car! Step 3: Adapter Plate. For example, analysts estimate that the Chevy Bolt EV sits at around $28,700 to build. They are not all equal. And it does vary from electric car to electric car. The first thing you need to do is get a car. Remove anything related to the gasoline internal combustion system. Step 1: Get a Car..