The value of the Concept Car is that it is unique. You say Concept Car, but you might want to go with Prototype. I did quick wiki search...
A concept vehicle or show vehicle is a car made to showcase new styling and/or new technology. They are often shown at motor shows to gauge customer reaction to new and radical designs which may or may not be mass-produced. General Motors designer Harley Earl is generally credited with inventing the concept car, and did much to popularize it through its traveling Motorama shows of the 1950s.
Concept cars never go into production directly. In modern times all would have to undergo many changes before the design is finalized for the sake of practicality, safety, the meeting the burden of regulatory compliance, and cost. A "production-intent" vehicle, as opposed to a concept vehicle, serves this purpose.[2] They are also known as prototype cars, but should not be confused with prototype race cars such as the Le Mans Prototype.
Concept cars are often radical in engine or design. Some use non-traditional, exotic, or expensive materials, ranging from paper to carbon fiber to refined alloys. Others have unique layouts, such as gullwing doors, 3 or 5 (or more) wheels, or special abilities not usually found on cars. Because of these often impractical or unprofitable leanings, many concept cars never get past scale models, or even drawings in computer design. Other more traditional concepts can be developed into fully drivable (operational) vehicles with a working drivetrain and accessories. The state of most concept cars lies somewhere in between and does not represent the final product. A very small proportion of concept cars are functional to any useful extent, some cannot move safely at anything above 10 mph.[citation needed]
If drivable, the drivetrain is often borrowed from a production vehicle from the same company, or may have defects and imperfections in design. They can also be quite refined[citation needed], such as General Motors' Cadillac Sixteen concept.[3]
After a concept car's useful life is over, the cars are usually destroyed. Some survive, however, either in a company's museum or hidden away in storage. One unused but operational concept car that languished for years in the North Hollywood, California shop of car customizer George Barris, Ford Motor Company's "Lincoln Futura" from 1954, received a new lease on life as the Batmobile in the Batman series that debuted in 1966 on the ABC Television Network.
That Could be part of the Fun of the Run, when the Runners find out that the "Concept" car Barely goes more then 20kph
If the Troll is in the Car, KE could just try to pull them over for that. Maybe have the runners try to get out of the situation by using Social Skills at first. Have KE check their Fake Drivers License, SINs. If that fails..
I felt one of the mistakes I made when I first started GMing was that I had a Linear plot set in mind for players. I now try to keep things more open and not try to force them down the plot I have written up. I try to anticipate what they are going to do, so I'm not blindsided as much, but when I write up stuff now, I usually include a few options for the way things could possibly go.