Race Technology

I've just installing a Dash 2 display only dash with Autronic interface into a street driven vehicle . Do i use a constant 12 volt supply to the dash and the interface , if so will the dash be on all the time or will it go into a sleep mode when not in use or can i use a switched power supply (only powered while engine is running). Thanks for any info

Ignition power is needed otherwise it will drain the battery.