Well the UBS report that you reference but don't cite pins the battery cost of the Bolt at $10 200. Surprise, that's close to the $11800 when you buy it as a spare part. Anyway, Things the Botl has but the Sonic in it is base configuration hasn't : SiriusFM Radio, Solar absorbing windshield, LED stop and tail lights, heated outside mirrors, 17"alu wheels, 6 speaker audio system, 6 way seat adjustements for driver and passenger, electronic cruise control, 8" screen, powered windows, OnStar Crisis Assist/Emergency/... OTA update capable, There is also nearly $7000 of R&D and depreciation baked in the Chevy's price which the Sonic obviously hasn't due to different product/life cycles. The Bolt has aluminium parts, the Sonic doesn't. It has a frame that must carry 30% more weight etc. Really you can't just claim that both must be the same cost to produce beyond the drivetrain.