When a Formula One car crosses the finish line first, it's the result of a long line of events. There's the mechanical aspects of the car, and all of them have to be equal or superior to the competition to achieve success. Powerplant, suspension, electical components, all that stuff.
To get that extra one percent advantage that results in wins, we see many uses of cool ideas. Mass dampers, flexing wings, anything to get that "unfair advantage".
Personally, I believe the organization behind the car matters the most. You have to have a management that is willing to take chances, push the boundaries and go into new territory. Hmm, maybe Toyota's problems could be a result of it's management structure. Things happen fast, changes can take place within hours. The company has to be able to react immediately to correct any shortcomings, and do it without faltering. Last year, ferrari had problems with their gearbox. They had replacements flown in IMMEDIATELY, those components had to be on the plane the moment the phone calls started.
1) Avoiding major blunders
2) Car preparation
3) Flexible and quick reacting management
4) Competent mechanics and engineers
5) Getting the car to the finish line
6) Tire management
7) Quality driver

Willingness to take risks
9) Aero package
10) Powerplant
10)