It's not going to run your high powered audio system.

I can imagine someone using it for a street racer or a car that gets taken around the block for fun, but I'd stay away from it if this is your "daily driver". I can't imagine it cranking the car over that well and when you are sitting in traffic and your alternator isn't recharging the battery because the car revs are too low, you'll find yourself stuck the next time you want to start your car when you're out at the mall.
A better option would be to move it to the hatch area, especially if you have a fwd car. This will help with the weight distribution and make your front driver lean more towards oversteer than the typical understeer with these cars...
You know.. It always cracks me up when I see ricers put double decker wings on the back of their civics, especially when they don't have any extra downforce on the front end (air dam). All they are doing is creating a worse handling car because Civic's are front wheel drive cars and tend to understeer. The wing counteracts oversteer and creates extra understeer. Besides.. Where are you going to drive a car on the streets at the speeds where a wing like this would even matter anyway?
Sorry.. Off on a tangent..
Sal