You can't just leave such incorrect statements on a forum unchallenged as they will be perceived to be 'true' by readers in the future, a forum is an historical record.
To make my point clearer, and why I suggested that you have never even seen inside a car radio - car radios don't have tuning capacitors (they are permeability tuned - variable inductors), they don't have ferrite rods (it would be useless inside the Faraday cage of a car, and the permeability tuners are the tuning inductors anyway). They are all also superhet designs, a TRF set would be unusable in a car.
As for 'super engineer', while I wouldn't suggest any such thing - I have won three national servicing awards, Grundig Satellite Engineer of the Year once, and Sharp TV/VCR/Audio Engineer of the Year twice.
If you truly want to start repairing old car radios, I may be able to help with service information for some of them?, particularly as we're in the process of clearing out most of the old paper manuals.