Smoothness of V6 compared to S6 engine.

I hope Japan have nothing to do with building it!

Due to weight and size of shielding it's never going to be workable. Never mind the cost.

Even though a very powerful car can use 1MW (for a few seconds at a time) a 100Kw car still needs the full critical mass of fuel so the core will cost the same (making all cars cost the same).

There is a massive lag between power demand and generation. It takes time to bring a reactor up to temp and then produce steam to drive a steam turbine that turns a generator. Rapid uneven thermal changes result in thermal buckling of structures. So it needs a series hybrid system as a car's average load is only 25-30Kw at M-way speeds and under

Dustbin sized core powers UK submarine fleet. Fuelled for life of 25 years. (Maybe 50Mw) It's still not viable for private shipping.

Then every time there is a pile up there would be a full Nuclear incident.

Sure man, I think we know all that. Unintended consequences and all that. Scientific optimism going overboard. A reminder when we embark on new horizons, such e.g. as fracking and gm food stuff. But also remember 'who dares wins'. Somebody always has to make the first start.