CPO for me is a nice hedge against the potential, albeit small, of major repair work. CPO would hopefully be useful for potential issues like a waterpump, head gasket leak, excessive wg rattle, injectors etc etc. All in all i've found it to be quite useful, i've had pads, rotors, two O2 sensors, filters, plugs, and an oil change all done under CPO since purchasing the car last May. IIRC $0.00 out of pocket for any of those things, only cost to me was an unrelated invoice for a new strut bar. My dealer is pretty well run and they try to accomodate you, for ex. the plugs and oil were done several thousand miles early. All in all i'm happy with CPO, gives me piece of mind on a car that frankly is not reliable.
E88 N54 Alpinweiss/Coral Red/Motiv HTA 3586r Tial .82AR/Motiv Port Fuel/Meisterschaft Race/Berk Resonated/ER CP/Synapse/VRSF FMIC/Rob Beck PCV Valve + Cap/ST Coilovers/M3 FCA + Tension Rods/M3 Subframe Bushings/M3 FSB/AA Strutbrace/DINAN Camber Plates/Apex ARC-8/Project Kics/VAC Hubs/Rogue Transmission Mounts/Alpina TCU Flash/Icarbon/#Tee CF Stuff/Kerscher/BMW Performance