King Brilliant. A singing teacher I once had said that the voice was like a bamboo stem. The straight bits between the joins were notes that could all be sung the same way but then you'd get a break (like the joint in bamboo) and the next few notes after that would be sung differently until you hit the next break. Part of learning to sing was learning the best way to sing each note. The higher nores will resonate more in the mask, your face, and the lower notes will resonate more in the chest. It will be different from your lower notes just as the expression in your speaking voice is different from the expression in your alto singing voice. So keep singing away in your car finding out what works where. Just be sure to stop if you do something that hurts.