In every game modding community there's always one vehicle/weapon/item that's done over and over again.
In all versions of CounterStrike it's been Glocks, Desert Eagles, M4's, MP5's, and AK's in that order, with at least 75 to 100 of each weapon.
In Day of Defeat and DoD Source, it was the sniper rifles, then the Thompsons, then the BARs that were overdone.
In GTA-3, Vice City, and San Andreas it was Nissan Skylines, mostly R34's that were overdone.
In TDU unfortunately it's Veyrons, I've got 26 different veyron files in my Bugatti folder, and I think I'm missing a few of the older ones.
The bar is set fairly high at this point. The best thing I can think of to beat the current "best Veyron" is the convertible Veyron from TDU-2, and link the windows to the removable hardtop. Drop the windows while driving, and the removable top retracts backwards and shrinks into the body. Make sure the interior colors work, both paint colors and the stroke color works, the front and rear wheels are the same size, and the textures aren't mega-dark and you've got the number one Veyron spot locked up.
And that's just an IDEA, not a request, so don't get your panties in a twist over it.
I just don't see the point of a 13000 poly shadow model when the exact same shadow could be obtained with a 3000 poly model, maybe even less than that.
The CPU is the ONLY thing that sees the shadow model, and a 13K shadow is going to run at a slower framerate in the game than a sub-3K shadow.
The best and easiest thing any modder can do to see what they do and don't need in a shadow model is to find a plastic model car, or even a hotwheels or matchbox car will work, and a flashlight.
Turn the lights off and shine that flashlight down onto the model at angles that match the sunlight in TDU. Pay attention to the details you see, and the details you DON'T see. Things like sunken gascaps, ridges on the hood, details inside the grill, flush headlights, detailed window trim, those kinds of things are NOT going to cast a shadow, especially in TDU's limited shadow engine.