BMW 430i GC lease strategy - possibly broker wanted

Hi guys,

I’m looking to get into a 2018 430i GC lease. I’m located in NorCal.
I found a specific vehicle at a nearby dealer (online) which matches my specs and has an MSRP of ~56400$.
It’s color is the fancy snapper rocks blue metallic as seen in this deal for example (this is not the exact vehicle I’m looking at, but same color): 2018 BMW 430i Coupe *NEW* - Nor-Cal - Today Only - $409+Tax, $1,000 DAS - *SOLD* .

The vehicle I’m looking at is manufactured in 2017 and has been a while on the dealer lot already. Also the 2019 4 series is already released, which may bring down the 2018 model prices a lot.
I was wondering what you guys think is the best strategy to go forward to negotiate with the dealer the MSRP down? For example should I negotiate myself or should i go through a broker? (NOTE: I haven’t contacted the dealer yet, so all options are open).
I’m aiming to get 20% Off MSRP before incentives - do you think that’s possible or unrealistic? I’m not really in a rush and if I don’t get a very good deal on a 430i in this color I can wait a couple of months or get a completely different lease.
If some broker is willing to help, please let me know.
I can share the details of the specific car I want via PM.

Thanks for everyones help and opinions!

If it’s a loaner, that is a realistic goal. If it’s new, I doubt you can get more than 14% off.