In my 20 years as sales manager, I have seen them come, and seen them go. Plenty of them. Made many into successful managers and top performers. I train on rapport building as "part" of salesmanship, but have never seen a salesperson take rapport building TOO far. Until now... I have counselled and discussed that rapport building is great but TOO MUCH RAPPORT CAN BE LETHALLY DEADLY to a car deal. That being said...

I am not looking so much for a discussion, as I am some material, articles, etc on: 

"When/How is building too much rapport, a bad thing" for a car sale. Any help would be greatly appreciated. I have SOME material but am always "looking" ;)