The latest on Mayfield from Fox sports. NASCAR says Jeremy Mayfield has again tested positive for methamphetamine and wants the federal judge who lifted the driver's drug suspension to reinstate the ban. The positive result from a July 6 random test was included in a U.S. District Court filing Wednesday. The filing includes an affidavit from Mayfield's stepmother, who claims she personally witnessed the driver using methamphetamine at least 30 times over seven years. NASCAR says in its filings that the "A" sample had levels of methamphetamine consistent with habitual users who consume high doses. The filing also claims Mayfield and his attorneys have failed to select a qualified laboratory to test the backup "B" sample.