Awesome Work!2-Thumbs Up on Your Experiment & Conclusion Thereof!Maybe a Jig set-up on a piece of Plywood,to hold the canister& a hinge on 1 side,& another thin piece of plywood the heighth of the heater,To make an L-shape,that is lined on the inside with Thermal ply,facing the interior of the Car.That could keep the Dash plastic safe & Radiate the heat,where it's needed possibly?Darn Good Work,CHEERS!