I think you would be losing about the same cargo space with a small box as you would with a basslink.
The box is about 10x10x10 and the amp can be mounted on top of the box or inside the right compartment since you dont have dsp...
The basslink is Dimensions (H x W x D): 14-1/2" x 12-1/2" x 8"
Just trying to help, i was going to do the basslink but did the research and the thing is just a peice of shit for the price. You could get 5x better performance by going with individual sub/box/amp setup.