[genefitz]

The people at best buy are idiots. Go to crutchfield, or ebay, and get the proper harness for your radio. You will not have to cut any wires, you wire the new harness into the radio, plug-n-play.
You will have to use the DIN kit, because the opening is double-din, while the radio, I am assuming is single-din.
The connection the moron at Best Buy was talking about is not on the Aveo. He is thinking of the Cobalt and higher lines where the radio stays on until you open the doors, then it shurts off. The Aveo, neither my 2005 LS or my 2008 LT have that option.
If you use the standard Chevy Aveo (Daewoo) radio wiring harness, it will work without issue.
On a side note, stay away from Best Buy and Circuit City. Their "Installation specialists" give a whole new meaning to the term "Special." If you want to find out something about Car Stereos, go to a professional shop, not some 18 year old snot nose'd kid trying to work his way through his college courses or fund his new bong. ;-)