You can't predict that kind of thing but you can tell which cars definetely won't be classics because they aren't distinctive or successful enough. When a car is first released, you don't know if it will be successful or not, but the cars of the 80s and 90s (which aren't yet classics) have had their day, and the ones that didn't completely take off or stand out won't be remembered. Even something like the Rolls-Royce Silver Spirit (which was a top luxury car in it's day) won't be as highly regarded as the older Rolls-Royces and it's not as good-looking.