Infinite Class Trucks:
To get this you have to complete the first 27 tracks in single race mode.
Pro Class Trucks:
To get this you have to complete the first 9 tracks in single race mode.
Dodge T Rex:
To get this you have to get first place in season 4 of career mode in the power division.
Rod Hall Hummer:
To get this you have to get in first place in all divisions in career mode.
Shelby Dodge Durango:
To get this you have to get first place in season 4 of career mode in the speed division.
Humvee:
To get this you have to get first place in the first 3 seasons of career mode in all divisions.
Monster Truck:
To get this you have to complete all 36 tracks on the hard difficulty setting in single race mode.