First of all, I am sorry that you have to declare bankruptcy. I also would like to tell you that I am not in any way a consumer lender and hopefully will never be

In addition, I think that you should visit the following forum
http://www.creditboards.com/phpBB2/ I have found it a good resource for people that have questions related to credit and bankruptcy.
My opinion on your situation is that you need to evaluate how much you need the car as opposed to how much you want the car. The thing is that your credit is going to be destroyed and I don’t think that you will benefit much if any from keeping the lease. You got to make some calculations and find out what would be best for you regarding transportation. Do you need a relatively new car? Could you do with a more modest method of transportation?
Bankruptcy is a way to wipe the slate clean, and is an extreme measure that should not be taken lightly. I encourage you to go to the forum referenced above and talk to people that have experienced for information. They can also point the best ways to rebuild credit after.
Hope this helps