RE:RE:Amount of Zinc in a average automobile
PMATSI: You are correct that aluminum auto bodies would not require Zinc. However, due to the higher cost of aluminum over steel and the greater complexity in manufacturing (different stamping and welding processes than steel) aluminum bodies will only be used on a higher end vehicles.. An example is Tesla where the Model S (low volume, high price) has an aluminum body whereas the Model 3 (lower cost, higher volume) will be built using steel bodies.
https://evannex.com/blogs/news/112953413-tesla-model-s-vs-tesla-model-3-aluminum-vs-steel-infographic
Car manufactures continue to reduce the weight of a car by using more HSLA (High Strength Low Alloy ) steel which does require Zinc for corrosion protection.