I had earlier avoided the cassette adapter because I wanted a solution that would work in all the cars that I regularly travel in, and because the cassette adapter was, at $30 in reputable shops, the same price as the much more technically advanced (and therefore interesting) wireless modulator. This changed last weekend, when I found a cassette adapter being sold for only $5 at Strathfield (annoyingly, their website does not have prices, but you can peruse their catalogues online for some details).
The flimsy plastic pseudo-cassette fitted nicely into my car's totally unused cassette player, and sound from my mp3 player duly followed. It also created an annoying clicking noise of similar volume and rate as my indicator signal, but this was easily taken care of by opening up the cassette and removing all the winding cogs (which I assume are necessary for some cassette players, but are not needed for mine). I prefer the cassette adapter to the wireless one because
- it doesn't need to transmit electromagnetic radiation into my leg, which rests against the wireless transmitter
- produces higher quality sound
- doesn't need power, and
- doesn't need to be disconnected when the car is started
So, that was $5 well spent.