In case anyone is lazy:
1 gallon = 4 quarts - you need 5 for a complete oil change w/filter
Rebate limit is 2 per household
On a related note, Castrol Syntec is on sale at Autozone - 5 quarts + fram filter (junk it) for $32 out the door. This means....German Castrol is in on it too. No rebates to deal with.