Allinurl question

Is there a problem with hyphenations in URLs when using allinurl?

[brandboerge]

I thought "allinurl:[string]" would show all pages with the string in the URL.

But this doesn't seem to be the case. Compare these searches:
[google.com...]
[google.com...]

With this:
[google.com...]

To me it looks like the allinurl-command doesn't work if there is a hyphenation in the URL? Or rather, that Google interprets the text strings on each side of the hyphenation as two different strings that should be in the URL, but not in that order?

I've tried another search with mercedes-cars (stupid example, but it exists) - compare:

[google.com...]
with
[google.com...]

What do you make of this?