Heya. I'm trying to think of what could have caused that. By the way, what is a PS2 ..?

Could anyone have taken your car out for a spin while you were away? As far as I know, the only thing that can cause flat spots like that is locking up the brakes at high speeds.. only we have ABS... So I don't know what it could have been.. maybe someone was doing donuts with your emergency break in the rain.. I dont know... My old car had low profile tires but no ABS and I did get a flat spot once from slamming on the brakes...

Maybe you have a defective tire. I'd say that's a good bet. Tires shouldn't get flat spots after sitting for a week. Call the dealer at least and ask the service department what they think. Sounds like a defect that could be covered under warranty to me.

You could also jack it up, pull the wheel off and look at it. That's easy enough.