Do you do your own oil changes? If so, then you will want to get in on this rebate. Green Earth Technologies is offering a $26 mail-in rebate when you purchase 5qt. of G-Oil Synthetic Motor Oil at Walmart. Click on over and print your rebate. According to the rebate, this should make your oil free.
Update: It looks like the link to the rebate is currently unavailable. Keep checking on it, as it seems it is a database error.