I know it's not a "sedan", but a great "spec" class is the Tamiya mini class that me and Derek and Tim and Rod (and maybe Corey) plan to run this fall.
So, if any spec racers are planning on investing in a new car this fall, I'd propose the Tamiya minis -- they are inexpensive, fun, tough, simple, and the racing is great. Less stuff to break and less stuff to tune make it a great spec class.
I'll have a loaner/rental available if anyone wants to try one.
I've posted info on the "early indoor classes" thread under "Winter Racing League" if you want more info.
Or, google Tamiya Mini Swift for more info.