What makes tape sound better than vinyl ?

Its impossible to get audiophile sound from a car system.

Maxell Metal Vertex is the very best cassette tape, and my deck is not even specifically calibrated for it.
I'll get Otari or Studer open reel deck in time and then the turntable, any turntable, will not sound better in any aspect. I will also be able to play master tape dubs if I can find them. 
Yes, I too think the resonances in vinyl playback is a big factor, but I suspect it's not the whole story.

Its impossible to get audiophile sound from a car system

True, but you can Audiomobile sound..close enough. 

All important recordings are originally on tapes, R2R. Is it just me who still after all these decades keeps wondering why this best media never came popular. Vinyl records, c cassette tapes, CDs and all that modern digital finally put the R2R into museum, so to speak... Shame, isn´t it ?

BIG SHAME !!!
But it's not in museum, there is a number of people very serious about R2R recording and playback.
Vinyl is great for archive, though, and back-up.