625 ILCS 5/3–401(a) ; 625 ILCS 5/3–402(B)(2)(a). For that reason, we and other courts have previously upheld stops based on the absence of car registration information in the computer database. See, e.g., United States v. Mounts , 35 F.3d 1208, 1213 & n. 4 (7th Cir. 1994) ; United States v. Cortez–Galaviz , 495 F.3d 1203, 1205–06 (10th Cir. 2007) ; United States v. Stephens , 350 F.3d 778, 780 (8th Cir. 2003) ; cf. Delaware v. Prouse , 440 U.S. 648, 663, 99 S.Ct. 1391, 59 L.Ed.2d 660 (1979) (noting that traffic stop is justified when there is reasonable suspicion “that an automobile is not registered”).Miranda–Sotolongo points out some innocent explanations for the vehicle's registration not appearing in the law enforcement database.

We review the decisions of the district court on the government's Rule 404(b) evidence for an abuse of discretion. United States v. Mounts, 35 F.3d 1208, 1214 (7th Cir. 1994), cert. denied, ___ U.S. ___, 115 S.Ct. 1366, 131 L.Ed.2d 222 (1995). After the government provided notice of its intention to introduce evidence of the earlier half-ounce cocaine deal, Walton moved in limine to preclude this evidence, contending that the jury would assume his involvement with drugs from the participation of his mother and the fact that the transaction had occurred at his residence.

Conspiracy to possess with intent to distribute cocaine is a specific intent crime. United States v. Mounts, 35 F.3d 1208, 1215 (7th Cir. 1994). Thus the evidence is directed toward establishing an issue other than propensity and the first prong of the test is met.

The district court found this testimony to be purposefully misleading, especially since Ontiveros omitted this fact from his own affidavit. A finding of perjury by a testifying defendant will support an obstruction of justice enhancement under sec. 3C1.1. United States v. Dunnigan, 507 U.S. 87, 90 (1993); United States v. Mounts, 35 F.3d 1208, 1219 (7th Cir. 1994), cert. denied, 115 S.Ct. 1366 (1995). We review the district court's determination that Ontiveros obstructed justice for clear error.

Tangentially, Waldemer argues that the prosecutor, in making the same argument described above, effectively accused him of the crime of obstructing justice, with which he was not charged. As Waldemer did not make this specific objection to the trial court, we review it for plain error — we will reverse on this issue only if the district court erred so seriously as to result in a miscarriage of justice. United States v. Mounts, 35 F.3d 1208, 1221 (7th Cir. 1994). The context of the prosecutor's argument, including his statement that his proposed inferences were instructive as to motive and intent, does not convey the impression that the prosecutor effectively accused Waldemer of obstructing justice.

In rejecting the defendant's motion to suppress, we emphasized that his theory was promising but his proof lacking: if, we said, a future defendant could bear the burden of making “a demonstration” based on evidence that the database in question “is unreliable,” that “might well form a persuasive basis for a suppression motion.” 495 F.3d at 1209;see also United States v. Mounts, 35 F.3d 1208, 1213 n. 4 (7th Cir.1994) (if the defendant had shown that “a large percentage of registered automobiles ... did not appear on Georgia's computer system and that this fact was common knowledge” the case might be different, but in that particular case the defendant “did not make such a showing”). Today, we find ourselves facing a good deal more directly the problem we anticipated—and on which we reserved judgment—in Cortez–Galaviz.

See generally United States v. Smith, 308 F.3d 726, 739 (7th Cir. 2002) ("[J]urors are presumed to follow limiting and curative instructions unless the matter improperly before them is so powerfully incriminating that they cannot reasonably be expected to put it out of their minds."). We do not hold that it was necessarily an abuse of discretion for the district court to refuse to repeat its limiting instruction, though it surely would have ameliorated the situation had it done so. Compare, e.g., United States v. Butler, 102 F.3d 1191, 1196-97 (11th Cir. 1997) with United States v. Mounts, 35 F.3d 1208, 1215 (7th Cir. 1994) (weighing the value of the "district court's careful and repeated instructions to the jury"). But we do find that, given the context-specific facts of this highly unusual case, the district court's failure to explain its decision to grant the government virtual carte blanche to introduce all the Rule 404(b) evidence that it did was an error that was not adequately cured by the limiting instruction provided.

We are therefore unpersuaded by Millbrook's argument that the prior conviction is too dissimilar to be admissible. See Macedo, 406 F.3d at 793 (rejecting defendant's claim that prior act was too dissimilar because it involved cocaine and current conviction was for methamphetamine); United States v. Mounts, 35 F.3d 1208, 1214-15 (1994) (upholding admission of prior attempt to purchase cocaine despite "significant" differences from charged conduct). Finally, we agree with the government that the probative value of the evidence was not outweighed by its prejudice, which was lessened by the district court's limiting instructions.

While we acknowledge that nine years is a substantial amount of time, the temporal proximity of the prior acts to the current charge is not alone determinative of admissibility. See United States v. Wimberly, 60 F.3d 281, 285 (7th Cir. 1995) (admitting prior bad act evidence that occurred thirteen years prior to charge when evidence was highly reliable and relevant to credibility); United States v. Mounts, 35 F.3d 1208, 1214 (7th Cir. 1994) (permitting admission of drug purchase which occurred seven years prior to arrest to prove element of intent). Defendant's argument that the events are not sufficiently similar because the 1992 transaction involved cocaine while his current conviction involves methamphetamine is also unsupported by this circuit's precedent.

While we acknowledge that nine years is a substantial amount of time, the temporal proximity of the prior acts to the current charge is not alone determinative of admissibility. See United States v. Wimberly, 60 F.3d 281, 285 (7th Cir. 1995) (admitting prior bad act evidence that occurred thirteen years prior to charge when evidence was highly reliable and relevant to credibility); United States v. Mounts, 35 F.3d 1208, 1214 (7th Cir. 1994) (permitting admission of drug purchase which occurred seven years prior to arrest to prove element of intent). Defendant's argument that the events are not sufficiently similar because the 1992 transaction involved cocaine while his current conviction involves methamphetamine is also unsupported by this circuit's precedent.