I want to start off by saying I'm a reasonably intelligent woman who isn't usually backwards in coming forwards. But I am a sucker for sales people and utterly crap at negotiations. It wouldn't surprise me at all if I tried to negotiate and ended up paying more for the ticket price of something 
sales people also intimidate me unlike any other, I don't know why!
Anyway, I'm off to test drive a car I've fallen in love with tomorrow, I met the salesman today (nice chap, but he's very salesman-y, if you took all the salesmen in the world and created a median salesman in a machine, it would be this man). I looked in the car, and providing it runs well I really want to buy it. It's about £500 more than I want to pay (it's £11k) and I want to knock him down a bit. How do I even approach this, and when? What words do i used? Any tips on knocking him down would be much appreciated