Salesman said he would reduce $1,000 if I financed.

He said I needed to wait 4 months to pay it off. Then the insane rate of 9.75% came back. I'll be losing money on a $43k loan if I pay 4 months interest. That's more than $1,000. What happens if I pay it off In a few days? I didn't see anything in the contract about it but I didn't look closely either. Is it there? A penalty?