There's also the added benefit of increased sales via replacement vehicles.
I believe that well over 200,000 cars are stolen and never recovered yearly.
Your belief is tin foil hat grade silly. They don't build them because people don't want them. If people did want them, Onstar vehicles would be the number one sellers on the market and every manufacturer would be rushing to jump on the bandwagon.
Unrecovered cars are stolen for parts which are used to repair wrecked vehicles which would have to be replaced by a car purchase if not fixed or they are stolen for sale to foreign countries which would have to buy cars one way or another, stolen or not.
Theft doesn't really increase total car sales, it just shifts the costs and profits from citizens to criminals, which is the purpose of crime in the first place.
I doubt you want to give up your pet theory, but it's true.