The CEL turned off, however I didn't like it either. Possible low voltage issue, which did not make me feel comfortable considering I wanted my wife driving a safe car with 4motion in the snow up here.....the weather here in the winter is crazy up here.
But hey, that's why they offer a 30 day money back guarantee, and it really is no questions asked! Didn't hurt to try it out.
Now I have my eye on the Jetta GLI or a 2013 CC with DSG for myself . Haven't driven the GLI yet but from how the CC was, I can imagine the GLI is a beast. I prefer the styling and luxury that the CC offers, and it had plenty of power to push me back in my seat, even with the AC blasting.