I don't know the situation of the market in the states but if definately works out much cheaper to buy used in the UK. Mercedes are great for depreciation, but if you wait twelve months the savings are amazing.
I'm sorry for stating the obvious, i know you know a lot more than me about this because i'm only 18 and i'm sure your quite a bit older than me, but in my experience my dad has been wounded buying new cars. We bought a new Jaguar XJ Executive in '96 for about £32,000 when we traded it in a year later we got about £13,000 for it.
Sorry to stray from the subject of the original thread but i just get carried away!!!