One trick I've noticed is that while watching the free 2 minute preview, click the fast forward button once on your remote. You will be able to fast forward thru the entire film. At least this works on my Roku 2.
While you won't be able to watch anything past 2 minutes at normal speed, you'll at least be able to see if the film is in the proper aspect ratio or not, as well as get an idea of picture quality.
I wish Vudu would give at least 3 minutes free, because the credits of so many films last over 2 minutes. It really helps being able to see a part of the film before deciding if you want to buy it or not.
The Warner Bros owned films, of which THE YEAR OF LIVING DANGEROUSLY is one, are prime culprits for CinemaScope films being blown up to 1.78 pan and scan. Some that come to mind are RIDE THE HIGH COUNTRY, HEARTBREAK RIDGE and THE IRON GIANT. There are also some 20th Century Fox titles that are shown this way. THERE'S NO BUSINESS LIKE SHOW BUSINESS is one of the Fox titles that's been re-formatted. They should only offer films in their original aspect ratios, or possibly offer both versions, especially since they're offering the films for sale.