Todd I think the credits mostly go to the car owner and not the manufacturer. Nearly a half of a trillion federal dollars has been given to subsidize the gas and oil industry since 1918 so in comparison, any solar, wind geothermal incentives to date are de minimis. EV subsidies are part of the federal subsidy program in the efficiency section of the budget (same part that subsidizes efficient refrigerators).
I'm not arguing that it is the best process, but it makes sense for the future. Gas and oil are just going to get more scarce, dirty and expensive. We need alternatives and EVs are one. They truly aren't perfect but are getting better. I would welcome a hydrogen powered alternative, but because of the energy density complications, I suspect that is further away.
ZEV credits, or Zero Emission Vehicle credits are given to the manufacturer by the federal government, at a rate of about 4 or 5 ZEVs per zero emission vehicle. Tesla and/or other electric car manufacturers then sell those ZEV credits to car manufacturers who need to buy them to satisfy manufacturer emission requirements. They are an indirect subsidy to electric car buyers from ICE car buyers.
I am all for REAL zero emission vehicle credits, but current electric cars, such as Tesla are an environmental nightmare. There may not be any emissions coming from the car, but the environmental cost to manufacturer the car and batteries and recycle huge batteries is 4 times the environmental cost to manufacturer, maintain, and recycle an ICE car.