whats dat techno song called in the new Saab commercial the one with the 9-3 reborn saabs

Unfortunately, u cannot buy this song. The production company that worked with Director Joesph Kahn is the one that came up with that tune (called The Orphanage). Here is a recent article is text on the subject (and yes, this is related to the latest music by Brittney Spears):

Joseph Kahn is known for his kinetic visual flair & keen understanding of vfx; his “Toxic” music video for Britney Spears won the Visual Effects Society Award for Outstanding Visual Effects in a Music Video. About his experience with this spot, Joseph Kahn comments: “The Orphanage executed the very demanding task of finding beauty in an act of evolutionary destruction. They brought a compelling level of design artistry to an ambitious idea. l had a great experience working with them.”