Well, I ended up cutting pieces to size for the fluid container which becomes a nice shroud that fits over the tank. I've left the instructions and sizes for that with pictures in another post somewhere here on the forum.
As others mention, it doesn't make much of a difference by itself, the pipe from the PTC heater goes straight into the car with just about a foot (30 cm) of rubber tube.
I've just finished insulating the rubber hoses with 22mm foams, quite a chore, the bottom protection plate for the power steering was pretty easy to remove, just 4 push pins. I also had to loosen de left front wheel arch inside cover which is put in place with about 10 or so of screw push pins, a bit more finicky as that is not easily removed. I just wedged it out of the way so I could get to the rubber hoses next to the fuel pump.
You can loosen the heater fluid tank by unbolting the brace from the car, the 2nd top bolt is unfortunately hidden behind the plastic windshield wiper guard. Just pop the push pins from that plastic strip (you can leave the one under the wiper) and you should be able to pick a #10 socket with extension under there for the bolt. Also, who had the bright idea to put the fuse box behind the heater fluid, it's neigh impossible to reach.
So what's left is removing the under tray that protects the heater. Unfortunately the 2 jacks we had didn't give enough clearance to work comfortably that far down the car so I left that for a later time where it's a bit easier reached.
I've also put a piece of 3mm thick foam with reflective foil side under the drivers side floor mat. Remove the door sill startin from the front and then working to the rear, the rear has 2 hooks for behind. Remove the small plastic flat head bolt from the front door arch plastic cover, just keep turning left without pushing, it'll come off. Gently pull off the cover.
I left the right side of the floor mat in place, I've found that adequate, stuck some thing double sided carpet tape on the floor (vacuum first) and then proceeded to wrestle the insulation into place. Mitsibishi wasn't entirely stupid, the left foot rest is a styrofoam block, so that's some basic insulation right there
When the foam is in place and rolled out to under the pedals, up against the steering column, you can wrestle the floor mat back into place and cut of the remaining insulation sticking out.
The seat heater from ebay is on order from China, and I'll be putting one of them under the floor mat to heat my feet, it's supposedly 30Watts per sheet, and I got the adjustable model with 5 settings to find out what works best. It seemed like a good idea to put reflective foam in place for this purpose.
