Well, those 667 MHz can be justified. AFAIK, the PII-333 had 333,33 MHz (FSB 66,67 MHz * 5), whereas the PII-667 had 666,67 MHz (FSB 66,67 MHz * 10). If you round these numbers, you end up with 333 and 667.
Concerning license plates, Germany is not that conservative. In fact, many ppl have 666 on their license plates - the funniest thing is that many of them are some boring conservative idiots who don't have the slightest clue what this number is about. I've also heard rumours saying that the house number 666 gets skipped, but I know from my own observation that these rumours are bullshit. It exists just like 664 and 668.
Many ppl are hilarious in that respect. In school, we once succeeded in convincing a girl in our class that the inverted pentagram around the neck of a Heavy Metal guy in our class was in fact a David Star...

she was really impressed and wondered in what way that guy was linked to anything Jewish... 9_9
It's not just America, that's true. But America is among the most hilarious countries in that respect. They got drive-in churches, and at school or in Disneyland or wherever, they can force you to wear your T-Shirt inside out if it has the logo of some Metal band on it, while at a store some blocks away you can buy Nazi acessoires adorned with "beautiful" swastikas... We had a student exchange with a partner school in the U.S. at our school, and when our guys came back, they told us that little story...
Not to forget all those morons who seriously blamed Marilyn Manson for the Columbine massacre. And yet, the US are the home of bands like Cannibal Corpse, whose stuff regularly lands on the index here (and sells great nonetheless).

What a country... so full of contrast and contradiction - it's really fascinating. I can never get enough of it.