An extra product has two costs to examine: its purchase price and any interest you pay to finance it. Ask for the dollar price before deciding whether the coverage is useful.
Calculate the add-on's impact using the same tax amount, cash contribution, interest rate, and term with and without the product.
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A $1,200 product can mean $1,429.09 in payments
In this fictional example, borrowing is $33,100 with a $1,200 add-on, or $31,900 without it. Both scenarios use a fixed 7.1% annual interest rate and 60 monthly payments. All other inputs, including tax, stay unchanged.
| Cost added by the product | Model result |
|---|---|
| Purchase price | $1,200.00 |
| Increase in regular monthly payment | $23.82 |
| Additional interest across the loan | $229.09 |
| Additional total payments | $1,429.09 |
The model rounds each month to cents and adjusts the final payment. Multiplying the displayed monthly difference by 60 may therefore give a slightly different total. These are hypothetical financing inputs, not a market quote.
To reproduce this result, choose Trade-in with debt in the checker. That example contains the $1,200 add-on and the $33,100 balance. The result reports the product's incremental cost. Change Optional add-ons to $0 and recalculate to inspect the other scenario. Do not change cash or term during this isolated comparison.
If removing the product changes tax, an incentive, or the offered rate, request a revised quote and compare both complete scenarios. The tool's single-product impact holds those inputs constant. It cannot tell you whether the dealer will keep the other terms.
Evaluate the product separately from the loan
The CFPB identifies optional add-on products as a negotiable part of a car purchase. Ask for each product and price separately. CFPB guidance
For a service contract, compare the coverage dates, exclusions, deductible, repair authorization, and responsible company with your existing warranty. The FTC distinguishes a separately purchased service contract from a vehicle warranty and warns about overlapping coverage. FTC service-contract guide
For GAP, read the specific coverage and exclusions rather than assuming the entire remaining loan will always be paid. CFPB GAP explanation
Keep a small decision record
Write down the product name, cash price, financed impact, coverage you need, and the contract section that supplies it. Leave an unanswered question visible instead of marking the product “checked.”
Suggested request: “Please send the product contract and a revised quote without this item. Show whether the tax, rate, rebate, or term changes.”
If already purchased, ask the provider and loan servicer for the applicable cancellation and refund process in writing. Do not assume a refund will lower the scheduled payment; confirm how it would be applied to your loan.
Keep your cancellation request, confirmation, and the later statement showing any credit. The calculation above measures buying the product at origination; it is not an estimate of a cancellation refund partway through a loan.
Use the OTD worksheet to verify that removing a product actually changes the purchase total. Then use the offer comparison if other financing terms also change.
