If it helps I can let you know what I just negotiated on my lease..
I just leased a 2012 Z touring with sport package sticker was around 42k
negotiated the price of the car to around 39.5k.
Then we began to work on lease prices and it turned out to be
39 months
2500 down
419/month
first month was included in the down payment and ttl was separate.
Im expecting to have kids in the next few years and dont have a garage or else I would have considered financing the car, but I am going to need more room and a bigger ride in 3 years
needless to say I love the car so far.
Hope this helps you figure out more about your negotiations. I would have financed if I knew I would have time to actually use the car after having a newborn:P