Last night my daughter left her 2003 Honda civic running outside, everything inside was turned off, a/c, radio etc etc. After we turned the car off this morning it started right back up no problem...all we noticed is that it used a little big of gas...will we have any problems now???
Well now that you now that the car wasn't stolen I don't forsee any major broblems. The only thing you may want to consider is not leaving $20,000 iems up for grabs in your driveway.
Excessive idling can cause problems with the catalytic converter, but this usually takes many, many months of idling (like a delivery truck). I'd check the plugs and replace them as a precaution.