That big glass greenhouse on your SUV lets in heat, glare, and UV rays that crack the dash and fry your skin. Ceramic tint blocks the heat without blocking your cell signal, but it usually runs around $450 for a full vehicle. Shops get quiet in the winter, so that is when you will find the softest prices and the most flexible booking.
When you are buying add-ons like tint, you want to separate the price negotiation from how you actually pay the shop. Get your quote locked in first, then figure out your timing. A financing window just helps you smooth out the cash flow so you are not dropping four hundred bucks all at once.
That 0% intro APR is a deadline, not free money, and any leftover balance when the 15 months are up will suddenly start racking up interest.