Well, spaces are illegal characters in URLs.  I was pretty sure HTTrack handled
it okay, though, but maybe it has some trouble with the space in the
querystring section.

You may like to add to your ASP code something like this, if you haven't
already:

<a href="page.asp?car=<%=Server.URLEncode( "Name of the car" )%>">

The URLEncode will form a proper querystring parameter.