Using the IS32LT3175 can result in a 55% BOM reduction, a smaller PCB and increased reliability.  The LT3175 is a single channel, low noise, low-EMI linear LED driver which can be adjusted from 10 to 150mA.  It easily interfaces to a low-cost momentary contact switch for local master control of the LED light source.  A PWM signal from a remote automotive microcontroller can also drive the LED light source but it is subject to the momentary contact switch. All the features and functions are configured with simple resistors, there is no need for a local micro.  The LT3175 was designed for automotive applications and is fully AEC-Q100 compliant.