18: BMW 7 Series
Big, luxurious, and expensive. Those are the three attributes that come to mind when you think of the BMW 7-Series. The problem is that those attributes are not the most flattering qualities for a car and the 7-Series has lost popularity in recent years. One of the problems with the 7-Series is the complete lack of reliability that the car has experienced (via CNET).
There was a time when the 7-Series was known for quality, but when the 2003 model hit, there was an abundance of electrical issues within the car. Since then, the 7-Series has been on the chopping block when it comes to consumer shopping lists. The lack of quality and the extremely high price tag just make the car a questionable decision for most people.