on premium cars it is not unreasonable to get 10-20% off...no matter cash or lease...if you are not getting it than you are simply not negotiationg well...
It depends on the dealer. I've got good deals on Porsche, Lamborghini and Ferrari (in one case, CHF 100k off). But then the BMW dealer refused to budge on price and all I got was a set of winters
I am having major heartache with a car I bought off this company and would suggest that you do your own paperwork, get your own plates and get any car you buy checked over by a mechanic you trust.
You get charged for the luxury of having a car delivered to your door with a set of keys ready to go. Unfortunately you pay for this service and have to trust them that the car you bought is good - in my case the car has proven to be an expensive case of hubris on their part and I am pretty upset by the whole affair and cannot in all honesty recommend them.