Options to sell 7 months before lease end?

[hyde]

I had 36mo lease which ended last october. I re-leased it again for 12 more months due to lack of any good deals at the time.

Yesterday I got a cash offer from Carmax in-store that's slightly more than my current pay off (inc taxes), but they said they can't buy it from BMW. I have to pay it off, wait for title, then bring it in to sell it to them.

I went to Audi dealer to see if they can trade it in if I decide to get an Audi, they also said they can't deal with BMW and that I have to buy it first.

So now I guess I can consider dealing with BMW dealers and look into getting another BMW, but will they be able to take over the lease/buy it from BMW FS directly or will they require me to buy the car before I can trade it in?
Anyone has any experience with this type of advance lease-return or buy out? Or in case of new BMW, "upgrade"?