The WPFS SRT-8 wheel is spec'd at 20x8.5 for the 2005 & 2006 models. I am not sure if that was widened in 2007 or not.I ran the compnine on my SRT. Born November 9, 2005. I found it odd in the build sheet it says its equipped with 20x8.5 alloys. I thought that was the size for SRT-design, which was not available in 06???
Also try "compnine.com", they will list the cars equip sheet, all you have to do is provide the vin number. Great site and it's free.