According to the FCC rules (Part 15, subpart D), just about any low power transmitter is unregulated. Several years ago, the limitations for unregulated transmitters was that it had to be under 100mW (.1W) input power. I just browsed the FCC website, and they have made several amendments to Part 15 for other wireless devices like wireless network cards and other microwave devices. Lots of technical jargon and what not, so things have gotten a lot more complicated to determine the legality of the other frequencies. I would hope that the FCC has better things to do than to confiscate harmless RC toys at customs. I mean heck, I can buy a toy wireless microphone that broadcasts on the FM band (88-108Mhz) that has more range than a Bit! "Real" RC gear is a different story, because the transmitters have a higher power output.

A Bit clone that I purchased had a sticker on the box that claimed it was FCC compliant under Part 15 rules, it was a 40Mhz car - and it was purchased at Kay-Bee toys, a larger importer.

Just another side note, the Bits and other "toy" grade RC cars use different frequncies for running multiple cars because their receiver circuitry is not selective enough to allow separate "channels" within the same frequency band like the "hobby class" RC's. Thats why some people may experience problems when running frequencies that are close together.