A solid roof rack turns your car into a gear hauler, but those systems are pricey when you buy them at the last minute. The best time to shop is late summer, before the winter rush hits and retailers start hiking prices on seasonal storage.
You should view the rack as an investment in your weekends, not just a quick add-on. Factor in the cost of the bars, the mounts, and the locking mechanisms before you commit to a specific setup.
That 0% intro APR window is a deadline, not free money. If you have any balance left after the 15 months are up, the card issuer will start charging interest on the remaining amount, which can get expensive quickly.