Head on over to
http://www.autopia.org/forums/index.php and check out the detailing tips...
I am not saying that you have to use a Woolite solution to clean your interior... I am just sharing my experience and success story... Additionally, I use 303 Aerospace Protectant for UV protection- provides a nice matte finish without being greasy.
Sometimes you don't have to drop $10 for a cleaner... I tried a couple different brands of "interior cleaning solutions" and this is the best one - and by far the cheapest.
Oh, and the Mr Clean Erasers are amazing! They'll clean anything you can throw at them.