Car Audio and Video Market as of Q1 2009

I am looking for information on the market itself for Car Audio and Video use and sales during this last quarter to determine positive or negative growth of the industry.  It seems that a decrease in disposable income would lead to less customization and after-market purchases, but I want to see some figures on how the industry is doing.  If anybody can lead me to some documents or info, it would really be helpful.  Thank you.