After installing a new amp. My son noticed the reverse lights stayed on constantly, the airbag light on the console flickered, finally (after a couple of weeks) the car kept running when turned off. Any suggestions before I take it in so I don't get ripped off? Thanks!

Check all grounds first. Grounds are essentially vessels of witchcraft and other demonic activity that has actually had customers swear their cars were posessed. Next thing is to give the alt a check - a few threads I notice the user complains of weird and erratic electrical behavior, usually followed by a no-start situation (dead batt from dead alt)

yes i think there is a grounding problem also, try connecting the amp to a different circuit in your fuse box also [like the radio circuit] ... i think your amp is providing power to your ignition system....