Cars are expensive to keep on the road, and brakes are one of those non-negotiable repairs you cannot ignore once they start squeaking. Routine maintenance like pad and rotor replacements usually runs about $600 in the US, which is a tough hit to take out of nowhere when your car is your main way to get to work.
Timing the repair right can save you a chunk of change on labor, especially if you get your brakes checked during a routine tire rotation when the wheels are already off. Once you know what the shop is charging for parts and labor, you can figure out the best way to handle the payment without stressing your monthly budget.
That intro window is a deadline, not free money, so treat it like a strict payment plan. If you still have a balance left on the Discover it® Cash Back when the 15 months are up, standard interest will kick in on the remaining amount.