I must admit that I haven't changed cars for a while as my mileage has decreased dramatically in the past few years but I used to change them religiously every 3 years (i.e. warranty period) and, having an aversion to finance deals, the following used to work for me. Most of the big brands - Audi, VW, BMW etc - massage their sales figures by "pre-registering" thousands of cars to their dealers which appear as "sold" in the manufacturers stats. Every 6 months, around April and October, any remaining stock HAS to be moved on for the next allocation of new cars. That's when you will see the big promotions but be aware that any unsold after the cut-off date will simply go to auction and be knocked out at the best price they can get. My approach was to look up in the price guides the very best retail price for my old car, look at the worst price for a 6-month old used car, knock off a bit, calculate the difference and then go to the dealer and say "You can have my car plus £X" and then not budge. OK, the initial reaction is always a no - I had a dealer laugh at me - but if you're prepared to walk away, the chances are you'll get a deal. My previous "used" car had 35 miles on the clock when I bought it; the current one had a couple of thousand miles but I got it at a huge markdown (although I note that the paperwork showed the new car bought at full price and the old one sold at a ridiculous price on which I presume they made a 'loss'). It probably only works if you are dealing with the same brand.