I wish I could find more of these but they are the old model ones so finding 4 or even 2 more would be a great score let alone findinng dual 2 ohm ones.
I might just look at measuring up for a larger box that will be capable of holding 4 12's or a couple of 18's down the track and just make a new baffle when I can afford the larger woofers.
Affording to get more power is the hard part I have about $20 a week that I can save. Could be a long wait.
A clam shell would be nice but with only 4 drivers would look out of place I think. The car is barley a meter wide.