6500 dollars due at lease signing is nuts. I wouldnt put any money down on any lease. You wreck that car and bye bye to that down payment.
Id look at a 2006 or new lexus sedan. ES rides like a couch. GS rides like a sports car. The genisis by hyundia has been out a year or so and those started loaded in mid 30s. you could probably find one under 30K. Acuras got redesigned in the past two years so you can probably score the earlier design for good value and those are solid rides.
I would stay away from used bmw and mb bc of the upkeep costs but thats me.