It's a song by Mercury Rev called Delta Sun Bottleneck Stomp
The Chemical Brothers have done a remix of it, so it may be that it is their remix on the advert..
Sea t' corporal sea atlantic's too specific
haven't time t'settle sharks infest th' water
kickin' up th' dust constructin' new ideals
old ones laid t' rust nothin' seems so real
Slidin' away in a washed out delta sun
Missionaries flood my favorite AM stations
flowing in their futures washed out in this delta rag
look th' other way pocket all th' pieces
tripping up th' strawhat tumble inta th' wind
Slidin' away in washed out delta sun
Slidin' away in washed out delta sun
Wavin' goodbye i'm not sayin' hello