Owning a car means dealing with hidden wear and tear long before an engine light turns on. A bad tie rod or bad wheel alignment will eat through a set of tires in a few months, turning a routine maintenance job into a much bigger repair bill.
A full front-end wheel alignment and tie rod replacement runs about $650 at most mechanics. Taking care of it the moment you feel steering drift saves your tires, and spreading out the cost makes it much easier on your monthly cash flow.
Remember that an intro window is a deadline, not free money. If you still have a balance on your Discover it® Cash Back card when those 15 months end, the standard variable interest rate applies to whatever balance is left.