I added a wood platform under the driver's side seat to give me a place to store my water hose and electrical cable. In this location my version of T@B has the WFCO 8735 and all the wires running into and out of it, some water hoses, and the duct for my Atwood Furnace. Note the WFCO's housing is not vented at all, it's a solid housing, and it has a fan that blows air out the front if it gets hot.
I added wood supports to the bathroom wall edge, to the wheel well, and to the other two sides. The level is exactly equal to the top of the WFCO housing, so I'm resting the wood on that.
This method literally allows 50% of the usable space under the seat to be available for storage.
Here's the view from the top:
By bathroom wall:
Wheel well support:
By duct heading to furnace:
Next to AC outlet:
With wood shelf (1/4" plywood) installed:
Wasn't sure whether to add this to existing thread (
http://tab-rv.vanillaforums.com/discussion/632/under-seat-storage-driver-side) or start a new one, I'll make sure to add a link on that one to this post.