45+ minutes each way in the car is quite a bit each day, and since I can only stand about 1 in 7 new songs out I decided that it would be worth my while to listen to Chinese language podcasts as much as practical while commuting. Football season has made Denver sports talk radio interesting enough that I’ve slacked somewhat, but I still try to listen on my way in, and think that this background listening practice has helped me maintain my language skills well.
Listening to Podcasts takes some pro-activity, namely downloading them prior to listening if you are unable to stream. It would be ideal if you did aside from driving as well so that you could use a dictionary and/or rewind the tape, but something is better than nothing.
Here are my favorite podcasts (links in title are to relevant website, followed by RSS feed URL to copy into podcast program
德国之音 （Daily～30 min each) German News, generally about China and other international news. (http://rss.dw-world.de/xml/podcast_radio_china)
美国之音事实大家谈 (daily~20 min video) Washington DC based Voice of America Chinese. Generally about either American and Chinese relations, inner America topic, or something in China. (Link to list of all VOA Chinese Language RSS feeds)
BBC daily podcast— (~6-7 minutes)
东吴相对论（～30 min) Two guys talking about various topics, leans towards business topics, but regardless the hosts always bring up some rather thought provoking stuff, best of this group IMO. （http://dongwutalkshow.com/rss）
锵锵三人行 (~25 minutes） Been a while since I’ve listened, but they start with a （relevant?) topic like foreigners pissing off bridges in Shanghai, talk about it for a bit. Only updates once a week or so. (http://feeds.feedburner.com/qq3_aac)
新闻酸菜馆 （～1 hour) Comes out once a week, a guy and a girl talking about a prominent topic but get off track occasionally, girl’s laugh is annoying but overall a nice change of pace from the others. (http://since1989.org/feed/wasai)
ITunes and other Podcast programs have search functions so you will likely be able to find others that you may find to be of more interest. Please comment if you have other favorites.