Bought it for seatbelts, looks good for heat shielding too

This is Johnson & Johnson 'All Purpose Cloth Tape'. I originally bought this stuff for making seatbelts, but I took a shot and it looks like it will work well for heatshielding as well.

http://i4.photobucket.com/albums/y106/SteveK2005/Seatbelttape.jpg
That is colored with a Sharpie. It might be tricky to feed into the buckles in most racing harness sets, but it will stick to the cage itself, and looks great.

http://i4.photobucket.com/albums/y106/SteveK2005/DSC01001.jpg

http://i4.photobucket.com/albums/y106/SteveK2005/DSC00999.jpg

http://i4.photobucket.com/albums/y106/SteveK2005/DSC00994.jpg

http://i4.photobucket.com/albums/y106/SteveK2005/DSC00992.jpg
In those pictures I just stuck it on and burnished it down with a Q-Tip, toothpick, and the handle of the clippers (Small, hard, and smooth edge). It's been a couple of hours and it doesn't look like it's lifting at all. I tried coloring with a silver Sharpie, but it's not ink like the red one, so it didn't work as well. I think some thinned sliver paint would work, and that might also help keep the edges from fraying (Wicking some ultra-thin CA/superglue into the cloth might work too).

Steve,

That looks quite good for both applications. Where would I find such tape? Pharmacy, hardware store?

looks good! nice find!

Yes, you can get it in the first-aid section of any grocery store or pharmacy, at least here: Not sure what you might have available in other countries.

http://www.bandaid.com/tapes.shtml
Top row, all the way to the right.

I have only seen it in 1" wide, but I'm sure they sell them in wider rolls. You'd probably have to go to a medical/athletic supply place, or even ask your doctor if they have any nearly empty rolls you could have.