heh- owning a 2000 E39 (same setup) the cable is the backup for a really goofy elektromekanik throttle.
But you're right, there's a cable off the pedal, and it goes to the throttle body. What happens there... is best left unmentioned...
like the trombone section, if you don't look at it, it usually minds its own business.
As to fitting hanging pedals, the difficulty is that the 2002 dash is not structural. I suspect, with the padding, that may be intentional
to allow it to collapse if you're thrown into it. But there's not enough native structure to take the force of a panic stop footpedal.
And when you go looking for structural things to attach to, there's...
well, there's the left side inner fender, the right side inner fender, and not a lot else.
This started out as a very light car indeed.
Even the brake booster assembly contains its own forces- note the brace to the abovementioned stout inner fender.
And this carried through- much later models have significant pedal boxes added to transfer the loading,
and have a history of flexing and cracking.
Me, I adapt the foot pedals, and use my ankles to drive. I've come to like it, over the E30.
t