Does the ATS RWD car have an open differential, or a physical limited slip differential?
I would take a RWD limited slip differential equipped car with Good Quality Winter Tires over an AWD car with open differentials, traction control, and all season tires every single time.
That's why I bought winter tires for my RX-8, and did way better in the snow that anyone with a FWD or AWD car on all season tires, taking off from lights, and going around corners.
That's also why my new CX-5, with AWD, has a set of snow tires mounted on the stock wheels, when snow season returns.
Now, a RWD car with an open differential is nearly worthless in snow, winter tires or not, in my opinion.
BC.