<xsl:template match="/cars">
  <xsl:variable name="modelcount">
    <xsl:for-each select="car[generate-id(.) =
generate-id(key('by-model',model)[1])]">
      1
    </xsl:for-each>
  </xsl:variable>

  Total no of models - <xsl:value-of
select="string-length($modelcount) -
string-length(translate($modelcount,'1',''))" />

</xsl:template>

--
Joris Gillis (http://www.ticalc.org/cgi-bin/acct-view.cgi?userid=38041)
Laudeo W3C et dona ferens