I just found an EQ for my EPIA board. I found the latest audio drivers for it, installed them, and there was my EQ.
I'm not sure if it was there before installing the new drivers, but all that matter is that I have it now. If your mobo has the matching chipset, you can find the VIA Stylus drivers here:
http://www.viaarena.com/?PageID=69
-> Launch the "VINYL DECK" from START->Programs->Vinyl Deck. Once it loads, click on the Sound Effects tab.
I still wish this functionality was built in to the car media players, but it's better than nothing.