Nice spec. My better half is a fleet manager and I have asked her about discounts given that the leasing companies she deals with have massive negotiating power. She tells me that 8-10% is about the best you can hope for. Less on some models/ more on others. Bear in mind she leases more cars in a year than most of us would buy in a lifetime and they are primarily Prestige brand cars. She also told me there are always deals to be had on "one off" cars direct from the importer from time to time. These are either cancelled orders or are cars that have been highly specified as potential demonstrators. Of course you don't get colour choice with such cars and they often come with "delivery" mileage. Before you all tell me leasing is not the same as buying the cost of the lease is directly related to the purchase price of the car so she pays close attention to the discounts available and meets regularly with the factory reps. Also in the UK the vast bulk of car sales is to leasing companies. This is sometimes why dealers appear so uninterested in the private buyer, fleet sales dominate the market in the UK.
