Sentence and conviction of conspiracy to distribute methamphetamine and possession of methamphetamine with intent to distribute is affirmed in part and vacated in part where: 1) the district court erred in denying the defendant's motions to suppress evidence found during searches of his person, car, and home solely on the basis that the defendant, who was on probation for a nonviolent offense, was subject to a Fourth Amendment search waiver at the time of the searches; and 2) the district court's failure to suppress the unlawfully seized evidence was harmless as to the conspiracy conviction, but the court could not conclude beyond a reasonable doubt that the evidence did not contribute to the jury's verdict on the possession-with-intent-to-distribute count. and 3) the district court did not make explicit findings, as required by Fed. R. Crim. P. 32, to resolve disputes regarding the sufficiency of the evidence to support offense level increases at sentencing for importation of methamphetamine (U.S.S.G. § 2D1.1(b)(5)), maintaining a premises for the purpose of manufacturing or distributing a controlled substance, U.S.S.G. section 2D1.1(b)(12), and unlawful discharge of a toxic substance, U.S.S.G. section 2D1.1(b)(13)(A).