Some dealerships like GM, used to also have a bank. GMAC. Ford w/ FMC.
A car that's sold for 12-14K, has a general margin of 10-15%. Some as low as 5%, but still.
The 0/1% is also hard to obtain, needing to have good credit and possibly sizable downpayment, but don't worry they have options if you sign at the dotted line.
The fact that you think they make no money on 0/1%, is you falling for the marketing.