Update: Now, the promotion is valid through 3/31/13
Discount Tire Direct offers $50 Instant Savings on Select Sets of 4 Tires or 4 Wheels valid thru 3/25/13. Shipping is free. Thanks BfnC
Note, the best deals are when the manufacturer rebate up to $80 on select tires or wheels stacks with the $50 Instant Savings.