Today we had a dozen Gen1 Prius's on our property. Ok 5 were parts cars for our shop but 7 Gen1's is still a lot in one place at the same time. Most cities in America don't even have 7 Gen 1's, in Boulder there are dozens of these still running around. see photo on Facebook Boulder Hybrids - Boulder, CO - Automotive | Facebook
...I saw 4 Gen1's in my survey of 130 Prii in North Virginia. The all looked marvelous, like new. Here the Gen1's got the best free HOV access, forever. although the owners can buy a newer version and transfer plates.
My wife and I were in the Denver/Rocky Mountain area in 2010 and I was really surprised by the number of Prii that we saw, Gen I, Gen II and new Gen III's. Especially in the Rocky Mountain National Park area. Toyota had donated Gen II's to the park rangers but there were also many in private driveways. I also passed a lot of travelers on the park roads.