What should I do to find out if my car has been cloned, which is necessary to take steps to discover whether or not there is like, so I expect that the lone practice this is discovered or in vehicles is no longer practiced?

Car cloning is just duplication of identitiy of a car.
To confirm wether your car is cloned or not depends on which country you live and the way the government regulate registration. If the car is cloned by an expert the car has to be inspected by an expert to be confirmed wether the car is cloned or not.

here a link that may give you a better idea about cloning.http://www.youtube.com/watch?v=ALWqy6Rb2Ps
do not esitate if you have a particular question.