OutlawFirebird

I saw one for sale and i looked at it and started to like it. the one im looking at is copper in color, and is a 05 ls 2 door, auto, Most of the reviews have been really good, there have been some bad ones but not even close as many of the good reviews by users and professional expert reviews. I do have some quick questions about this car though.

I have seen a ss with the bigger spoiler/fin on the back. Is it possible to buy one of those bigger spoiler/fin and put it on an ls cobalt? like swap the smaller one out for a bigger one.

What type of gas millage does these cars get?

What type of aftermarket parts are avaiable for the 4 cylinders? Like exaust, supercargers, etc.

any help would be great

thanks alot