Quick Charge is handy in just about any context, but it's especially useful in the car. With older phones on some roadtrips, using Google Maps navigation and streaming music at the same time actually made my battery power drop even as the phone was charging. With a Quick Charge-compatible car charger, that's no longer an issue. These upgraded chargers tend to be a little more pricey than their standard alternatives, but today Amazon has an Aukey-branded charge available for just $12.99. Add the coupon code 2P77G62C at checkout and you can take another $7 off the price, bringing it down to $5.99.
The Aukey charger uses Qualcomm's Quick Charge 2.0 standard, which is 9 volts at 2 amps. Take note: the new Nexus 6P and Nexus 5X don't use Quick Charge 2.0 - their rapid charging capability needs 5 volts at 3 amps, so even if you get the correct cable, the new phones will charge at the standard rate (or possibly a little faster), but not as fast as you might be used to with the proprietary Quick Charge 2.0. Most of the other recent flagships should work just fine.
If none of that dissuades you, remember to add the coupon code before you check out. This deal appears to be valid in the US only, but it does come with free two-day shipping for Amazon Prime subscribers.