[Cyberdemon]

Tell your brother to read through all the leasing info on this site and then go back and have them give him the real numbers. Every dealer I went to gave me the real numbers.

You need to know:
-Money factor (Interest rate) - Have him check his credit score on a site like Credit Karma to make sure his credit isn't killing him. If his credit is good he should get the lowest MF (Listed somewhere in this forum)
-Cap Cost of the vehicle - this is basically what they are selling him the car for, BEFORE rebates. This should be $500-1000 over invoice. He can find the invoice price for his exact car using BMWconfig.com, print that out and bring the papers with you so you can have a bartering point. Salesmen don't like informed consumers, but generally won't lie to you once they see you know what you're talking about.

Once you have that you can calculate the residual value of the car, and what the loan amount should be using a lease calculator. Also make sure they aren't burying some higher fees in there as well.