Instead of doing money down, you can put up to 7 multiple security deposits on your vehicle. Each security deposit is equal to your monthly payment rounded to the nearest $50 dollars.
IE: Payment $490 ---> $500 security deposit ---> $3500 maxed out security deposits
Payment $505 ---> $550 security deposit ---> $3850 maxed out security deposits
In the $505 case, sometimes it's a good idea to put a few hundred dollars down to lower your payment to under $500 to save some money.
Each security deposit lowers your money factor by .0007, for a maximum of .00049, which is a total reduction of 1.18% from your interest rate.
To compare the two using fictitious numbers:
$1000 down payment will lower your payment $20/month
$1000 deposit will lower your payment $12/month
Of course like stated above, you get your money back at the end of the lease, and if your car is stolen or totaled.