IMO the Police Spinner from the film looks like it could be an a more industrial evolution of the classic Mead Spinner, the concept art version looks like a cruder predecessor.
One element that stands out to me is the Mead Spinner has elegant compound curves in both glass and bodywork. Both the concept recreation and the Peugeot edition K uses have slab sided, faceted designs which sadly to me just scream 'budget movie car'.
Compound curves are expensive to produce and require more sophisticated production facilities- that is one reason I feel the Mead Spinner looked like it was a vehicle from a 'real' future. Designs like this are often too expensive to produce on a film/TV budget, hence the wonderfully advanced Type 7 Shuttlecraft from TNG was replaced by a slab sided Shuttle pod when they finally had to build a set prop for the show.
I do like faceted designs, but after seeing the Mead Spinner I would anticipate the newer model would be even more streamlined and curved, not blocky.