l am looking to get a used, but in good shape still, 2004/2005 BMW 330i. Price being from around 23,300 to 24,300. What would be a good amount to put down for the down payment? Would 6,000 help me in any way lower the payment cost and maybe the interest rate? Or what would be a good amount that can help me reduce those? Please answer about what is generally a good down payment for it, and then about the amount that can help me lower cost of it~ please and thank you!

The normal down payment should be 20% or more. on 24000.00 that would be 4800.00..
6000.00 down would leave you 18000.00 to finance.
l would not finance over 48 months, as the car would be seven years old when you pay it off..