Steering Wheel Vibrate problems of the 2010 Chevrolet Camaro

I have had my car for 1 year. When I get to 55mph the steering wheel shake so bad, it's unbearable. This have been going on since I bought the car. I took it back to the dealership and they said it was the alignment. They aligned for me. Well it ran pretty good for a couple of days and then it started back shaking. I also have a problem with the rotors or brakes or something to that nature. It sounds like a 18 wheeler when I stop. The rotors or something make some kind of wobbling noise when I drive. I turn the radio down quite often so I can hear if anything is coming off from the brakes. I'm not paranoid, because passengers in the car ask me all the time, "what's that noise". For me to have a decent car like the Camaro, I don't understand. Can you please run a thorough check on the tires, rotors, brakes on these cars. Also check the trunk too, because sometime my trunk won't open with the key nor by pushing the button on the inside of the car. I am concerned because I purchased a car over $30k and I'm not getting any enjoyment out of it. I'm scared to drive too far because the rotors or something may come off. Help please.