It is only when their value to the scrapyard exceeds what anyone might pay for it that we would see a marked improvement.

One other observation though.  Getting a Prius is tough - they just don't make enough of the things, they are expensive, and they haven't been around long enough for people of more limited means to be able to afford a used one.

Diesels are tough to get too - realistically VW is the only one worth having unless you want a big diesel pickup or SUV, but at least these have been out there for a longer period and getting used ones isn't as tough as it would be for a used hybrid.

There are however quite a number of cars out there that get > 30mpg.  By my standards, not great, but if you are moving up from an SUV it would be a pretty good deal.

I have a friend who is really into Vespa scooters, and he just bought a Honda motorcycle so that he has something more suitable for highways.  He was telling me the other day that it appeared to him that there might be more people on scooters out there.

I hear anecdotal stories about people simply moving closer to work.   You wouldn't really be able to tell by looking at the roads.  There is a guy at work who drives a Fornicator, but he only lives 5 miles from the office.  He could practically walk to work if he wanted to.