As an example of a commercially available model given some extra detail, here is my 'RIO' Rolls-Royce Phantom II 'Henley' roadster. It has my favourite feature of steerable front wheels, but I also added...
Suspension,
new glazing, New screen top-frame,
New screen mirrors,
New waistline trim,
New door handles,
New mascot that can be turned so the bonnet does not hit her,
...and loads more including wipers & motor units, lots of engine detail and the ability for the fan blade to revolve when the model is moved forward on it's wheels, a rubber drive-link from one rear wheel runs through the differential moulding and joins the end of the prop-shaft. At the other end is another rubber link running up through the engine moulding and connecting to the fan blade.
Enhanced wheels with additional detail as seen on the real 'Henley',
Bumpers designed for easier removal and probably some more I have now forgotten!
Now, I won't put as much detail onto the Bedford Van, but certainly steering and suspension, plus a few refined items like a road fund licence inside on the front screen and probably a road map laying on the seat, period registration plates and a radio ariel. All items I have done before on different models.
Please site mod, if this picture does not fit-in with the Opel thread "Teebodk" is running hear, you may move it or delete it.
Rollerman.