I haven't thought too much about next month's car(s) yet. However, I drove the BMW Concept 1 Series (on SH) in a DeadNuts race the other night and it was simply spectacular. It's not the flashiest car (although the carbon fiber hood and racing stripes are sharp!) but I believe it would do a very good job of reproducing the racing we've seen in the Sciyobaru cars.
Some other possibilities:
2014 Corvette Stingray
Ferrari 512BB
A Lotus of some kind?
Merc '54 300sl
S2000 GT1 Turbo
I'm going to stick to Premiums for a while because they're very easy to acquire and I'm trying to make this whole thing as accessible as possible. I'm also going to stick with mid-to-low power cars because I think they help keep the field a little closer (the faster the car the bigger the talent gap becomes). I'm open to options, and I like themes.