The rap stars trade verses until the wee hours
Scott Aukerman admits duo rehearsed act
Sacha Baron Cohen pulls stunt at California bash - watch the video
Dominic West collaborated with rap star on chart-topping album<br />
'Relapse' debuts at top of US chart<br />
Both rappers score fastest selling records of the year
Rapper gave away tickets on his Twitter page
Rapper opens up about drugs battle
Tickets for Detroit performance will be given away today (May 18)