What a financed car actually costs out the door in Oklahoma — the sales tax this state really charges, whether it credits your trade-in, and what the payment does to what you can borrow for a house.
In most states a trade-in reduces the amount you pay sales tax on. In Oklahoma it does not — tax is charged on the full negotiated price even when you hand over another car. Because the tax is normally rolled into the loan, you also pay interest on it for the life of the loan. The calculator shows what that rule costs you as its own line.
IMPORTANT — 4.5% is the SUM OF TWO SEPARATE STATE LEVIES, not a single rate found in any one statute: a 3.25% motor vehicle excise tax (68 O.S. 2103) plus a 1.25% state sales tax (68 O.S. 1355). NO LOCAL SALES TAX applies to the vehicle itself — 68 O.S. 2106 makes the excise tax 'in lieu of all other taxes on the transfer or the first registration in this state of vehicles', carving out only the 1.25% state levy plus registration, title and Corporation Commission fees. USED VEHICLES ARE NOT A FLAT RATE: the excise component is $20.00 on the first $1,500 of value plus 3.25% of the remainder, so a flat 4.5% overstates the tax on a low-value used car. The taxable value must fall within 20% of the average retail value in the guide the Tax Commission prescribes, or the Commission substitutes one.
Money factor, residual, and the payment — taxed by your state's actual method, since some states tax a lease's full value upfront instead of each payment.
Which dealer offer actually costs less over the life of the loan, and the rate at which they tie.
Income, savings, and debts in — max home price and qualification signal out.
A dealer offers 0% financing or $3,000 cash back. On a $38,000 car over 60 months the two cost exactly the same at 3.70% — and above that, the 0% wins by thousands.
Co-signing a $683-a-month car loan cuts the house payment you can qualify for by $683 — dollar for dollar. And if it defaults, you owe the whole balance, not half.
One number, in writing, itemised — and the scripts that get it. Every line a dealer can add, which of them are negotiable, and what your own state's tax rules do to the total.
One number, itemised, with the taxable amount working your state's trade-in rule live rather than leaving it to you to remember: four states with a sales tax credit nothing against a trade-in, and Ohio credits it against a new vehicle only. Checks a documentation fee against the nine statutory caps this site has confirmed, and is explicit that the other 41 states are unresearched rather than uncapped. Prices the F&I office as the optional extra it is, and adds the trade-in payoff back into the amount financed — because negative equity does not disappear when you trade the car, it moves into the new loan and accrues interest.