Nope they don't take much off at all off used cars unless they're priced too high to begin with
Lexus Stockport - £850 off. Chester - £1k. Cheltenham £750. Edgeware Road - Nothing. Bradford - £500-1k. Leeds - £500-700
Of course, if you buy a car thats been sitting around for ages or not in demand, that all changes. They pretty much know that RX's in good spec, NX and IS will pretty much sell themselves