You also know that Tesla has a waitlist for purchased cars, so changing gas prices do not impact immediate sales in any case. Thus, why the relationship exists

You also know that Tesla has a waitlist for purchased cars, so changing gas prices do not impact immediate sales in any case. Thus, why the relationship exists is an interesting question -- I think it's because investors assume the relationship exists, and then react strongly to market news, thus strengthening the assumed relationship. Maybe this is a good example of a feedback loop.