Hey I have a 2005 Cobalt LS and I bought it new. I now have a rattle in my dash behind my stearing wheel that i have had for a while. Now it has gotten louder and my stearing wheel shimmys and shakes really bad.....if it was just when I hit my brakes i would know the stearing wheel shaking would probably be my rotors....but it also does it when im driving down the road...along with the rattle under the dash and it has gotten louder. It has done it since i had new tires put on it. Im thinking maybe a alighnment might help becuz i didnt have one done cuz they didnt have enough time....we went in there like right before they closed so i had a certificate for one but i never had it done. yea i know big mistake...but does anyone think maybe they know what it is? Needs Alighnment or maybe a tire outta balance?.....I leave for a week in florida next week so i kinda wanna get it fixed lol. thanks

:screwy:

im having the exact same problem right now, it started a few months ago after i got my tires rotated...

Tires are most likely out of balance.

Rotate the tires again and see if it stops.