To the Limited Coupe auto deployed spoiler?

I was planning of trading my XFIREX for a brand new SRT-6 where I can get more power for the price of $8,000 after trade in. This is more practical than upgrading to Renntech, Kleemann or Evosport ($15,000 for 330 hp more) where you might lose your warranty. This process will give me 100 miles starting mileage, newer model, new wheels, more power and new warranty period since I have already incurred 24k miles in my XFIREX.

I love to keep the "boat tail" design which will be my priority to replace with the auto-deployed one after getting my new SRT-6 ride.

I have driven my 2004 Limited Crossfire to 145 mph and it don't seem to feel floating or unsteady at that speed. I have a 100 lb. speaker pods though in my trunk plus 2 amps in a metal rack.