I HAD a post/thread on here about Vehicle Financing. Can't find it now (I think it used to be a "sticky" before the migration to the new format). I guess it doesn't matter.
Never trust a dealer to tell the entire truth and give you the BEST deal if it's going to take money out of his/her pocket. They make $$$ on the rate you get. It's called Dealer Reserve. If the bank accepts an applicant at 5% and the dealer writes the note for 6% - and you agree to it - the dealer makes that 1% - in addition to what they make on the car deal. 1% may not sound like much, but if you're financing 35K over 5 years, it's a good chunk of change you could have used to buy mods for your car, or just reduce your payment.