All right. I looked it up and here is what the prize is decided on.
Eligible cars are new models released in the twelve months prior to the award. The cars must be available in at least 5 European countries.
Nominees are judged on the following criteria: design, comfort, safety, economy, handling, performance, functionality, environmental requirements, driver satisfaction and price. Innovation and value are also factors.
Seven cars make the shortlist on a simple vote and then the final round of voting sees each jury member with 25 points to distribute among the finalists. Those points must be divided between at least 5 cars with no more than ten to any one car. Apparently every jury member provides justification for their vote distribution.
So there you have it. I'm glad that there is published justifications. That provides more legitimacy.