Vehicle EconomicsCost of Financing Dealer Add-Ons Calculator
See the true all-in cost of rolling paint protection, VIN etching, or similar add-ons into your loan.
Why this comes up
Paint protection, VIN etching, nitrogen tires, and similar F&I add-ons get quoted as a single sticker price, but financed into a 5 or 6-year loan they carry real interest cost just like any other loan dollar. This engine isolates exactly what that interest adds.
How we calculated this
We run a standard amortization on just the financed add-on principal, at your loan's own APR and term. Because fixed-rate amortization is linear in principal for a shared rate and term, this isolated run gives the exact incremental interest, the same result as financing the whole deal with and without the add-ons and taking the difference.
Worked example, using this page's own defaults ($1,200 in add-ons, 7% APR, 60 months, no cash toward them): run the calculator above to see the exact interest and all-in cost.
What this means
- The longer the term, the more a financed add-on's real cost exceeds its sticker price, even at a fixed APR.
- Paying any cash toward add-ons at signing reduces this cost directly, dollar for dollar of principal removed.
- This is strictly the financing math, not a judgment on whether a specific add-on is worth having at all.
Limitations
This assumes the add-ons are financed at the same APR and term as your main loan, which is typical but not universal; a separately financed add-on could carry a different rate. See Methodology.
Methodology
This engine uses Vehicle Economics' fixed-rate amortization model on the isolated add-on principal. See Methodology for the full detail.