Adding LED pods to your bumper changes how you see the road at night. These lights take a beating from weather and debris, so it pays to buy quality once instead of replacing cheap ones every season.
Watch for warehouse clearance events at major auto parts retailers, which usually happen right before new model years or during seasonal inventory resets. You can often snag high-end hardware for a fraction of the list price if you keep your eyes peeled for these sales.
Remember that the 18-month window is a hard deadline. If you have a balance left over once the term ends, the bank will start charging interest on whatever is still owed.