They are also allowed to sell equity if they discover the need to do so. But preorders allow them to a) offer somewhat less equity and b) do so at a higher pric

They are also allowed to sell equity if they discover the need to do so. But preorders allow them to a) offer somewhat less equity and b) do so at a higher price due to the PR value of >1mm preorders. The pre-orders appear to have significantly reduced the cost of capital for the Cybertruck.