Found several helpful threads on removing a clear bra and tried everything suggested in those threads.
Unfortunately the clear bra on my car has been on there waaaay too long and there is just no taking it off the ways that are suggested. It has dry-rotted on the car - cracks are visible everywhere in the bra.
The basic problem is that the bra shreds as soon as I try to lift it off the paint. I can't get much more than a couple of milimeters up before it breaks off, leaving every bit of the adhesive behind.
The adhesive itself seems to have cured to the paint. There is no hint of plastic over the stuck adhesive, but using goo gone, 3M spray on adhesive remover, oils... nothing works very quickly. With a lot of elbow grease and about an hour of careful work, I was able to remove about five square inches.
I wiped down the exterior of the bra with some goo gone and actually observed it penetrating the cracks in the surface of the bra. Eventually it evaporated but at no point was the bra easier to remove.
I also tried an adjustable heat gun. Warming the bra didn't make it come off any easier, but it did begin to liquify the adhesive. I tried a range of temperatures but the underlying problem is the fact the that bra has started to decompose - the cracks don't allow the bra to be removed in a sheet. It keeps shredding into tiny peices.
Next up, I'm trying a drill mounted eraser. I could really use some advice or any other methods I could attempt. I'm not too afraid of minor damage to the paint. Pretty sure I can correct whatever I cause in the removal process.