NR2003 has what's called a box model. It's the outer perimeter of the car when it touches another object. So any mod must be the size of the cup car to act right on the track when it bumps into things.
Also, physics. Every legend car I have seen has a 1200CC motorcycle engine producing roughly 80 to 100 horsepower. The lowest horsepower in NR2003 is 450 HP.
The lightest car in NR2003 is 2800 lbs for the PTA physics.
So I don't see it happening anytime from any crew that I know of that actually makes mods.
Here is the thing, Physics don't matter. Look at the DTR series, still going strong after all these years, yet none of the mods really handle realistically. Hell 99% of the mods out there today for this game in reality drive nothing like their real life counterparts. For instance your DirtLM mod, there are no physics in this game that even come close to representing a DirtLM.
Legends car at 5/8th scale have....
125hp
1300lbs
So a mod for them scaled up to 8/8th or 1:1 scale would be (if my math is correct)
200hp
2080lbs
So you throw PTA physics under it and call it an "outlaw" series (like many of the non INEX sanctioned series are).