I would double check with BMW about the "CPO" status, especially from a non-dealer and perhaps the broker is just using the term in combination with the warranty info.
I was searching for M3's earlier this year and never came across a CPO vehicle.
EDIT: It appears there a lot of 2011's and some 2010/2009 in CPO status right now. Interesting as I saw none available 6-7 months ago.
2013 F10 535i M-Sport, Sophisto Grau, 6-speed MT
2011 E90 335i Sport, Jet Black, Sport Auto, Performance Edition
2002 E46 330i Sport, Jet Black, 5-speed MT, lots of upgrades
2001 E46 330Ci Sport, Steel Grey, 5-speed MT....and more
Last edited by Keyser Soze; 12-08-2012 at 11:31 AM.