Distracted driving is commonly referred to as the new drunk driving. It is responsible for taking human lives on a daily basis, teens' in particular. Smartphone use, particularly texting while driving, is the most dangerous form of distracted driving. In this paper, we aim to utilize smartphones to save human lives instead. In particular, one of the most common forms of distracted driving is adjusting the car radio while driving. We propose FM-Hop, a car radio station tuning system, which automatically adjusts stations on drivers' behalf, yet without any user involvement. FM-Hop utilizes an FM receiver in a driver's smartphone to scan available FM stations and automatically tune the car FM receiver, based on user preferences. Given that FM-Hop requires no external equipment to measure user distraction, it could be seamlessly deployed in existing vehicular environments. To evaluate FM-Hop on a large scale, we deploy a web-based framework, which enables us to tap into a large crowd-sourced user base. Our tests, conducted by more than 600 paid participants, show that FM-Hop reduces the number of station switches by 3.25X. Most importantly, we explicitly demonstrate that FM-Hop strictly reduces driver distraction.