these?http://cgi.ebay.com/OPTI1533D-Optidrive-15-High-Power-Dual-Voice-Subwoofer_W0QQitemZ270415283930QQcmdZViewItemQQptZCar_Subwoofers_Enclosures?hash=item3ef601c6da&_trksid=p3286.c0.m14&_trkparms=65:12|66:2|39:1|72:1234|240:1318|301:1|293:1|294:50
They look promising, I wish someone would try some
why don't you.
