Cars with turbine engines and flywheel *VS* Hybrids...

In the past, Chrysler had an experimental turbina engine. It even made
a few rounds around a major American race - I believe it ws some Indy
500. The turbine engined vehicle delivered exceptional economy, had
tremendous power (at a very high RPM), and they are very simply
designed. The only problem with turbined engines is that they only
work efficiently at high speeds.

Why not have a modified turbine engined vehicle now? During low
speeds, it should run on a mechanical flywheel, which stores energy.
At higher speeds, it turns on the turbine. Or alternatively, it's an
electric hybrid coupled to a turbine?

What are your opinions?

Also, why don't modern day hybrids not use flywheels to harness the
energy to be used during slow speeds?