So, what is Ford Flex Buy and how does it work? Itās simple ā financing is structured so that the monthly payments are lower than average for the first 36 months, then a little higher than the average for the next 30 months after that. What is Flex Buy financing designed for? Itās ideal for first-time car buyers who are perhaps just starting out at their job and expect to earn a higher income in the future. Or, it could be useful for those who are experiencing a temporary dip in their income but expect to recover eventually.