First and foremost this car is Assembled in the US with mostly Korean parts. Left over parts from other Korean Auto's after all they were designed there, with an Opel platform. The transmission sucks. The car was painted a couple of weeks ago(THE ROOF), seems it was caused from under the clear coat. Paint is a 3 stage water based process with clear coat GM states it will still look good after final payment to paraphrase. The transmission feels like its slipping and lunges as it slows down. I can feel all the shift points slowing down. Sometimes it wont downshift when hitting the gas. GM stated feeling shift points is the nature of the beast slowing down. With 8000K miles the car is starting to shake, especially with AC on, 4 bangers where noted for that problem 20 years ago. I use 93 octane to have any gas mileage. I also use 100% synthetic oil So far mine is or has acted up like most complaints and more. And this car is paid for how and who is going to buy a shaky car with ac on and the tranny acting up. I bought a chevy is the late 80s and it was the paint. I bought another in the mid 90s and it bounced down the road if you hit the brakes hard. Should have bought an auto 100% made in Japan I am sorry to say.

Update from Oct 17, 2013: Disgruntled with Chevy Sonic. Better known as buyer remorse. It shakes rattles and rolls. 2012 has more complaints that I have seen. The 2013 has very little. Its to bad that GM wont pass the information to the dealerships to correct these problems. They must. have done something to reduce problems on the 2013.

Most people think the dealership should be competent enough to correct the Tranny, the ruff idle with or without AC on. Mine Vibrates so much I can feel it in my seat idling , not to mention the vibration can be felt just leaning on the bumper. The car is going back to GM to add this to there list of problems. If GM fails to make the dealership aware of how to correct the problem, than the dealership cant do anything to correct the problem.

NO CODES no problem.. As mentioned before how is a person with these problems sell or trade these SONICS, with these drivability issues