Originally Posted by FS7
In order to get this achievement you need to get a contract from the team that is leading the constructors championship (if your team is leading the championship you won't be able to get it).
Best way to get this is to go to one of the lower end cars (Lotus, Virgin, HRT, your teammate will never score any points). Choose rival from the team that is leading the constructors championship, beat him, and you'll get the contract and the achievement.
Actually that is the "Hot Property" achievement you speak of....
To get "The Big One" you need to be leading the Constructors Championship (or be in the top 3 atleast) and it should unlock after you have enough points to win the World Championship.