DIESEL’S DENIM FRENZY: Speaking of Renzo Rosso, his Diesel brand will kick off its 30th birthday celebration on the morning of Oct. 10 by offering die-hard denim aficionados a limited edition pair of jeans for only $50. Diesel is manufacturing only 20,000 of its “Dirty Thirty” jeans, 8,000 of which will be available in select Diesel stores in the U.S. for one day only. The jeans will feature a back patch with the “xXx” logo, the dates 1978-2008 embroidered on the side and customized buttons reading “Diesel 1978.” Diesel also has added to the entertainment lineup for the finale of the brand’s 24-hour global birthday party the following night at Brooklyn’s Pier 3. Chaka Khan and Joel and Benji Madden will be performing, along with N.E.R.D, M.I.A. and Hot Chip. More performers are expected to be added.