This would be super hot if they just sold the item to you instead of charing installation. Last time this deal rolled around me and my bro were going to split some stereo equipment but they wanted to charge like 300 dollars for installation for a head unit and some speakers.
I tried buying a Pioneer Mp3/CD head unit and some 6 1/2speakers. I called them up on the phone and they told me it'd cost about 600 dollars total including that coupon. The head unit only cost about 280 speakers woulda been free. If you're cool about paying for the installation go for it.