Not 20k, but some have come under 30k, with relatively low mileage (83k km) such as this:
2005 Magnetic Blue Elise with Biscuit Interior - LotusTalk - The Lotus Cars Community
It's unfortunate how weak our dollar is now. If it weren't, it makes importing one of these bad boys a lot more tempting than buying early AP2s with 100k km for $25,000.