First, if you want short term increases in value a car is the wrong direction. I bought my Crossfire recently because once I drove a SRT6 I was hooked at any cost. My luck led me to an expert in your club that steered me in the direction of value if there is any. My luck found a 2006 SRT6 Coupe in the rare Machine Grey. A quick look at your handy statistics showed me that it is 1 of 47 SRT6 Coupes made in 2006. I saw that only about 6-9 actually made it to the US and only 2 were Machine Grey. 1 of those was shipped to Puerto Rico. I have the other one covered in my Garage.
I love this Car.
Like other things I have collected that are no longer made. Value is in quality,numbers produced, and condition. I have to keep this one original. Now I can look for a 2005 just to play with and learn. They are cheap considering what you get in good looks and performance.