Agree with you 100% Turbo, I'm guessing I'm going to do the same overhead install on my Sequoia. I have lots of space on the dash, but why not use that one? It's wasted space really.
And yes, I checked for clearance. You can go all the way down and back with my install. I made sure many times every step of the way. I'd hate to have to limit the functionality of the seat in any way. Strangely enough, I had more trouble with the PSU case I decided to use for the DSATX than with the Morex case itself. Also because of an electric motor in the right side too. After stripping the carpet, I had plenty of room for it there.
More pictures coming. I'm thinking about using an air conditioner vent to cover it all up. But first I'm still working on my "contraption" (the pieces of wood elevating the case by 3"). I want it to be able to withstand a fairly good kick, and the first tests with my 12 boots are good! I run two pieces of wood under the rails (forming an U shape), with the support in the lower part of the U, so if you kick it, mechanically you're kicking the seat rails themselves. I opted for this solution, to avoid screwing the case support on the side rails since screwing on wood/metal can become loose over time (unless you use nuts, but they would be a pain to access for maintenance), and may not withstand a kick like I'm giving it right now! (Almost) no screws maintenance: you just remove the pieces under the seat rails, and you can slide the whole system down (until the wiring allows), and so having complete access to the system in no time.