Does your car stereo still have a cassette deck on board? When was the last time you used it? Never? That's what I thought. But there's no need to let your trusty cassette deck go to waste, even in these digital times.
This Cassette MP3 player looks like a normal cassette tape, but it actually holds an SD card full of MP3s inside. You can use it as a portable audio player by plugging in headphones, but an even cooler function is its ability to be popped into any tape player and play your music like it's any other cassette. Now your car's cassette player doesn't seem so antiquated, eh?