Hi Kaz
This is the reply I got from the Michelin Customer Engineering Manager
"How desperate is the car for tyres?
If you can wait until August/September this year, we are launching the two sizes below in Pilot Sport Cup2 which would be perfect for the car.
So, if it was mine, and I could wait, I would. If it's urgent you could mix the PS2 & PS3, but they aren't the ideal combination"
Paul