How the Federal Reserve Can Change Interest Rates

The Federal Reserve can change an interest rate, but the interest rate they change is very like weird and esoteric. The overnight Fed fund rate determines how much money banks must have in their accounts at the end of each business day to avoid running afoul of the Fed. So if two banks need a set amount of money in their bank account that's what makes your car more expensive. And so why does that make my car market? Yeah, exactly.