Many years ago I saw kids' tape recorders that dragged a permanent magnet across the tape to erase it. Their head became magnetized but they sounded so bad that nobody noticed.
The last tape recorder I saw used such a high bias current for chromium and metal tapes that it erased any magnetism of the head.
News Flash: some people (particularly us college types) actually do have limited budgets and cars from the 90's. To contribute to my charity fund, send $25,000 in unmarked bills to my P.O. box.
Not sure if this is exactly what you're looking for, but Radio Shack (demag search) stocks them. Don't know if they ship international.
What a difference!
Canadian University kids drive brand new BMW's, Mercedes's and Jaguar's. They bought all the ipod MP3 players shipped to Canada and bought many more counterfeight ones. Their little brothers and sisters go around wearing big belt buckles with bright scrolling text. They also have MP3 players glued to their ears.
Actually it's been done! - a LONG!!!! time ago. Philips used to sell an in-car unit called an "Auto Mignon" (although I wouldn't swear to the spelling!). It was an in-car dash mounted unit that accepted 7 inch, 45 rpm, records!.
Yes, they were sold in the UK, in fact when I started work in 1971 we had one in stock at work!.
Bear in mind, they pre-dated cassettes or 8 tracks, both of which were fairly late. In fact, long before compact cassttes or 8 tracks appeared there were a number of completely different cassette formats - none of which (as far as I know?) ever made it to in-car.