Car Financing Guide

Car Finance Garage compares the real cost of dealer or bank financing, 401(k) loans, investment liquidation, and hybrid funding. The important question is not only whether a monthly payment fits your budget, but whether interest, taxes, rebates, and investment opportunity cost make one funding method materially better than another.

Dealer or bank financing

A traditional auto loan preserves your cash and investments, but the APR, term length, and dealer rebate structure can change the total cost by thousands of dollars. The calculator separates loan interest from investment growth so users can see whether keeping capital invested outweighs the financing cost.

401(k) loans and investment liquidation

A 401(k) loan may avoid a credit check and repay interest to your own account, but the borrowed balance is out of the market and may become risky if employment changes. Selling taxable investments avoids loan interest but can trigger capital gains tax and gives up future compounding. These costs are easy to miss without side-by-side modeling.

Hybrid strategies

Some buyers finance briefly to capture a manufacturer rebate, then pay down the balance from cash or investments. The hybrid model is designed for that kind of tradeoff: compare rebate value, short-term interest, tax cost, and missed growth instead of relying on the headline discount alone.

Continue to the interactive guide, or review the calculator methodology for formulas and assumptions.