for an instance i.e. car Toyota Sedan I have created a menu item.
the url in the browser looks like this:

xxx.com/cars/toyota-sedan-city

One can reach this instace also from the show all instances layout. The the url looks like this;

xxx.com/cars/toyota_sedan_city:21:32

Actually it is the same site which Google doesn't like as the same site can be reached by two different urls.

Any idea what to do?

Hi

there 2 things
1 - we need from URL recover Instance ID and Layout ID for show correctly this instance
2 - in Joomla CCK - you may show some instance in many way:
- in some layout
- in parent-child - view
- in joomla menu
- in all instance menu
....
And every time this will another URL which have full other settings for show - so we can't use same url for correct work

You may use component like sh404sef - for create redirect rules from all so urls - to some 1 url. But you need first check - these URLs show full same info and all same modules.

Regards
OrdaSoft team