If you didn't have anything in writing BEFORE the sale or on the contract, then you are barking up the wrong tree. You are on your own now, most people know how a dealer works once they get your signature or money.

I went with Tirerack.com for the F1 AS. Cheapest around plus they are/were offering a $50 rebate when you buy a set of 4 Goodyear.

I bought my car from a private individual knowing it would need tires very very soon. Knowing what the tires cost to purchase, I made an offer to purchase the car accordingly. I would never expect them to pay for new tires down the road for me.

Good luck, James