yeh, jasonh is right. i don't think all of it is tax deductable but some or most of it is. i think the only way to get 5% is if you have near perfect credit. realistically, i'd say the best rate a person with decent credit could get is 7%.
personally, i think financing through a dealership should be your last resort. i'd go through either an e-loan or try my bank first before i'd even think about going through the dealer. it's just one of the ways dealers can fool you, making you think like you're getting a low rate and then add on fees someplace else so that they still make money.
my mom was trying to lease a 2000 toyota corolla (ve model), which ended up being around 16k, i think (when it should have been around 13k). they made her put 1500 down, 60 month lease paying 250 a month. then you gotta add the residual which i don't even know what it was. but you get the picture. major scam right there. i went with her the next day to cancel the lease.
i don't know. i try to be careful with salespeople. that's why i am dealing through the fleet manager. they always seem straight forward with you.