Getting your car ready to sell means fixing the eyesores that make buyers lowball you. Door dings happen to everyone, but a clean side panel makes the whole car look well-kept and commands a better price. Spring and early summer are usually when people are shopping hard for used cars, so getting the bodywork done right before peak buying season gives you the edge.
When you are getting ready to sell, cash flow matters because you are likely about to buy another vehicle or tie up funds in a new title. Fixing the dents is an upfront cost you need to manage carefully. Negotiating the repair price with the body shop is entirely separate from how you actually pay the bill, so lock down your quote before you talk about plastic.
That 18-month window is a hard deadline, not free money. If you still have a balance left on the Citi Simplicity® Credit Card when those 18 months are up, standard interest applies to the remaining amount from day one.