These days, there is a wealth of shiurim available for free, online, in mp3 format. For those of us who drive a lot (like me) it would be great to be able to download these shiruim and listen to them in the car. However, most car stereos these days come with a CD player/radio that does not play mp3's (and many won't even play burned CD R/W's).
After doing a bit of research I found a great solution. Because the IPod became so popular a whole slew of gadgets have sprung up around it. One of them is the Belkin Tunecast (note: you can get it cheaper online at other places like Amazon). This is an ingenious gadget that you plug in to the earphones jack of your mp3 player and it broadcasts whatever the mp3 player is playing using a low power FM transmitter to your car radio. You find an unused FM station and you set it to broadcast on that frequency, you tune your car radio to that frequency and walla, you hear the shiur coming out of your radio. I tried it this morning on my way to work and it worked great. You just need to find an unused FM frequency which in Israel was not difficult (In NYC it might be more difficult) . It will work with any mp3 player, cd player, laptop etc. as it just plugs into the earphones jack. It comes with a power cord that plugs into the lighter so you don't even need to worry about batteries, all for about $30.