Affiliate Marketing Secrets

If I finance a vehicle through a loan company not affiliated with the dealership, can I finance the remainder with the dealership?
How do 3rd party auto loan companies work? Do you get the money first?
If I get say 8000 from a 3rd party loan company, can I use that toward a down payment on a car at a dealership, and finance the remainder of the car with the dealership?

“Roughly 85 percent of outstanding student loan debt is owed to the federal government. The remaining 15 percent that’s counted as private student debt is owed to various non-federal lenders, ranging from banks to loan companies like Sallie Mae Corp. to non-profits and state-affiliated agencies (under the Durbin bill, loans from any government-funded entity still wouldn’t be dischargeable, only those from truly private lenders).”
This story about student loans was in the paper today (Peoria Journal Star)