By "BMW USA involved" that means you called Consumer Relations and they gave the appropriate noises of "we will closely monitor", etc, etc? Or it there an active PUMA case and BMW is involved in directing the actual repairs?

I assume you didnt look at any records when you purchased the car and didnt have a PPI done? Just assumed the CPO would do all that? (not)

Not much you can do...what are your states lemon laws? Do you know? If it applies to you (if you are in the new car warranty period) and you hit the the threshold you might push there.