Plumbeeper,
they look great, but for heat testing I think you need to do a little more. I grew up in Las Vegas, and the Challenger was my daily driver from '81 through '86. Even in white paint, the interior got _hot_. Everything plastic/metal in the car was hot enough to be painful. I didn't have an IR thermometer back then (no consumer models, that was high tech stuff) but the ambient air temp would get to 145 degrees; the surfaces were hotter.
Does the material you use for filler hold up when it hits 150 plus? Does the paint/finish not get sticky if the car has to get parked in the summer sun with the wheel in full sun?
I imagine other SW folks have experienced similar conditions.
Please don't take this as a knock; its not. I will be back in LV someday, still have family there, and I certainly hope to take the Challenger. If it has to be in the driveway on a stinking hot day for a few hours I don't want to stick to the steering wheel like I used to to the vinyl seats