Your car is RWD, you should be running wider tyres on the rear to give a bit more traction / grip.
As mad082 has said, there is nothing wrong with running 235's all round.
If I were your I'd run
Front: 235 / 45 / 17"
Rear: 235 / 45 / 17"
Then you can rotate when ever you want, every 6 months, whatever...