The car is used, often just off-lease, but it's inspected by the dealership and minor repairs are done so it can be resold with the original warranty essentially reset as if it were new.
It is much more like how Apple, for example, sell refurbished devices that have been put back down a production line for remanufacturing.
I think the intention is for the remanufactured cars to be almost indistinguishable from a brand new car (as an Apple refurbished device is).
Make it look as new as you can, sell it at a premium as a "certifed" car, with maybe a 2-year warranty. Profit.
Even a 5 year old car is very unlikely to have any major mechanical issues unless it has been abused.
- Car starts
- Windshield wipers present
- Door locks work
- Key fobs work
...etc