removable sub parrallel to mono?

Hi, I am working on a boat that has a woofer that will be permanently installed into the cabins enclosure, and also will have a custom enclosure that will be built into a removable bench seat in the boats back open area. I would like to be able to switch from series to parallel so when the bench woofer is removed, the one inside will be at 2 ohm and when they are together it will be at 4 ohm. I have 2 dual 4 ohm voice coil subs. I am not sure what would be the best way to go about it. Would this work? Amp + output to woofer 1+ (sub wired parallel)    woofer 1 - to 30 87a to Amp- 87 to woofer 2+ (also wired parallel) woofer 2- to relay#2 87 relay#2 30 to amp- both relays 86 to fused 12v both relays 85 to switched ground Thanks for any help     

Radio Shack sells a plug similar to the following, but it is larger than this one and will handle more current.  You will have to buy 2 of one plug and 1 of the mate, Wire the mate into the system, then wire one of the 2 to the woofer that is to be removed, then wire the other one with a jumper wire that shorts the 2 pins when the aux woofer is removed.  Attach the jumper to the system wire so you will not have to look for it when you remove the woofer.

http://www.radioshack.com/product/index.jsp?productid=2103448