Since the BMW Longitudinal Front Engine vehicles (3-Series to 8-Series, same applies to the X3 to X7) have a very similar suspension set up, I say to save you some time, you should skip some time on the suspension 3D modelling and JBeam and just rip from the ETK 800 suspension, maybe use the adaptive suspension since this will be a grade above the 800 Series.
In the plan, the jbeams of rear suspension are modified ETK 800's, and in real, 5 series use double-wishbone suspension in front, so the front suspension needs a new model and jbeams will modified from Bastion's
I will never abandon it unless I lose files about it. I’m 17, maybe I don’ have time now, but I have much time work on it in future.