You do wonder if BMW think it's a good system. We just scrapped a system like this at work for the customer-facing staff, primarily because it was blatantly obvious that everyone was asking for top marks so it was a worthless exercise for reviewing.
Also makes you wonder how naive that sales guy was for mailing you that, especially as it was fairly confrontational, first thing some people would do is forward it on with a complaint. Although given the above that may not make any difference to BMW..
Either which way, sounds like you got a decent price and you've now got the car, so put it behind you and you can enjoy the drive while he counts his 4/5s..
