The IMCDb database lists only one car under the heading 'Italia' but there have been at least three different types of cars built with that name; two of which are in the IMCDb database.

Technically, the car listed as an Italia 2000
http://imcdb.org/vehicles_make-Italia.html
should be listed under “Triumph” as the ‘Triumph Italia 2000’.

Listed under ‘Intermeccanica’ is the “Intermeccanica Italia.” Which has appeared in at least three movies/TVshows. http://imcdb.org/vehicles.php?make=Intermeccanica&model=Italia&modelMatch=1&modelInclModel=- on

Hudson also made 26 cars called the Hudson Italia based on their Hudson Jet chassis – but apparently these have never appeared in any movies as they are not in the IMCDb database.

Unless one is talking to a Triumph-only crowd, or a Hudson enthusiast, any mention of a car called an “Italia” is most often thought of as referring to the Intermeccanica Italia (of which over 400 were built). Therefore, I recommend that either the IMCDb database include the Intermeccanica Italia under the “Italia” listing, or else the Triumph Italia 2000 should be moved under the “Triumph” category.

But for the Intermeccanica, Italia is the model name rather than the make/brand, no?
And for the Triumph one, was it sold as a Triumph? If it was just sold as "Italia 2000" it is normal that it does not appear as a Triumph.

They were hand made and wear strange name sometime. In some market, was the case in France, were sold as Ruffino Italia 2000, Ruffino as a make.
http://carcatalog3.free.fr/que18.htm