Hello. n00b here. I've been reading the forums for a while, but haven't joined. I think the massive amount of information here is great. I have a 2006 E60 5-series. I was about to purchase 2 dual head units to place in the front and rear, but I read in the other thread that this was not necessary. I just wanted to confirm that one dual head unit with one sensor in front and one sensor in the rear will not have any noticeable deficiencies compared to two sensors in front and two sensors in the rear? If that is the case, I'm about to save a lot of money. Thanks.