Where are you seeing the services listed? If CarFax that is meaningless. You could sail an oil tanker through the holes in reporting that a CarFax can have. I'm inclined to recommend the '06. If it has an automatic transmission it has a better performing unit than the '08. Get the VIN for the '06 and swing by the BMW dealer service department and ask them to see if they see any red flags. They probably won't let you see the report they have access to, but they should be willing to look at it and tell you what services it shows. With the '06 in particular you should get a pre-purchase inspection before buying. Good luck.
Present - '06 E90 330i sport; Past - '04 E46 ZHP, '00 E46 328i
www.bmwcca.org member #388003 - Use me as a referral & you could win a one day ///M Driving School!!