I'm wanting to get one of these little units because my car's cassette player is fairly new and I was too cheap to buy a cd/cassette/am,fm/ player unit. That said, it looks like these adaptor units are easy to use. What i want to know is are they all about the same or are there some that are better and more durable. It looks like they all use a cassette tape shaped apparatus to plug into the cassette player. Thanks all!