Hybrid motors take a lot of stress from the ICE during load changes. This makes the ICEs potentially live much longer. A lot of taxis areound here are older hybrid Toyotas. They must have at least 400,000km mileage already.
A taxi driver in Vancouver had a 2004 Prius and drove it 1 million kilometres with only regular maintenance and no failures. Toyota bought it back from him and took it to Japan to study it.
It looks like it wasn't the 1+M km version that they bought back, but the chap was an early adopter of Prius in that taxi role, and they bought back (exchanged?) his first one from 2001:
> For those working on the next generation Prius 2004 model, Grant’s taxi held invaluable information about wear and tear.They struck a deal: Grant sent his 2001 model back to Japan for testing and had a brand new 2003 model delivered.