2007 Chevy Cobalt Virbation

Fluids wouldn't have anything to do with vibrations from the vehicle. Although it is good habit to change your fluids at the recommended intervals which are in your owner's manual. Most common causes of front end vibration would be worn suspension parts. Seeing as how this is a relatively new vehicle, I don't believe that this would be the problem. Perhaps you should check your tires to ensure they are inflated properly, have good tread and check for any signs of unusual wear on the treads such as wearing only in one certain spot instead of all the way across the tread surface. Post your resluts and I will follow up.