I just bought a CPO 2007 E70 and I too have the problem of the "time" going away and needing to be reset. Also have a warning of "heavy battery drain" which is puzzling as all accessories are off. In addition I have the check engine light come on half way through each tank of gas, which goes away if I open the gas cap and re-seal it. The thing that made me the angriest was that the coolant level was down a full gallon and there are no leaks at all. It made me wonder what they actually checked to make it a CPO Qualified vehicle. It may be haunted as I also have an occasional beep, beep, beep. beeeep. (Three short and a longer beep) It is at the dealer now. Luckily I have my 535i to drive while they have it plus a 328i loaner for my wife.