Radio/tape Cd Player problems of the 2011 Chevrolet Suburban

While driving on the freeway at about 60 mph, my Suburban started to stall without warning, no lights appeared on my dash. Locks, radio and front lights started to go off and on and a complete loss of acceleration happened. When completely stopped the issue resolved. Still no indicators of anything wrong on my dash, proceeded to move the car out of the freeway and the same thing happened. Minutes later the car acted normal again. This could cause an accident.

1. )when we were driving thru the mountains our electrical system started to go haywire and the lights started going in and out and the ignition started to act up car turned off a few times we had to restart it when we brought it to the dealership to get checked out they said there was coins in the radio. 2. ) the defrosters for the front windshield doesn't defrost the window at all when driving in cold days the whole window fogs up and freezes making visibility to none and we have to stop wipe down the wind shield and drive again for ten minutes then this problem goes on and on the heater goes on full blast but no results that is a very unsafe and un drivable at times. Coins in the radio? I was astonished and very upset how could an industry make a vehicle that if water is spilled on/or in the radio or coins dropped in the cd compartment that the whole electrical system goes out and starts going haywire especially here in alaska a lot snow and harsh winter driving conditions are not great and if the vehicle stalls do to the radio and defrosters not working or someone spilled something on the radio then the people and children would freeze to death then who would be at fault that means the company that makes the vehicle is gonna be liable for the consequences the defrosters not working doesn't help any we have to drive thru this weather out here 9months out of the year and have to suffer because of these situations that is inexcusable and very dangerous to to public this needs to be fixed and resolved. We took it to the dealership a few times but the problem still consists doing the horrible dangerous things that the Suburban does we have another appointment to take the vehicle in again because the radio is acting up again and defrosters are acting up this is a defect and needs to be fixed.