[oldtamiyaphile]

Originally Posted by ShinyMew

I wonder how much of a difference it makes compared to white paint.

I have a white car with a black roof, I plan on testing the extremes later on, but I expect decent gains even from white, as chrome is still much more reflective.

Also, without an air gap below the newfound reflective barrier, won't conductive heat win in the end?

There's no conduction without heat (or a heat differential to be specific). By reflecting more heat, there's less heat energy for conduction too. If I park in the open and the sun is that low, then the sides will still be open for conduction.

You can find a few tests online of white vs dark cars parked in the sun, the white car always stays cooler, chrome is like white+. It stays so cool that the roof remains wet in the evening after a morning shower on a warm day.

Vinyl is also apparently a PITA to remove, especially from surfaces hammered by UV. I wonder if Plasti Dip with Silver Metalizer would work well or be easier to remove?

Plasti-Dip is expensive by comparison (in AU at $20+ per can), require masking off, and not as reflective.

The wrap is said to have a life of 3-5 years, but you can imagine that a matt black wrap (that tends to be all the rage) absorbs much more heat/ UV and therefore won't last anywhere near as long as chrome.

I removed the 'Jumbuck' lettering on my dark coloured ute after seven years, the lettering was all cracked and flakey. A bit of heat with the heat gun and it came off no problem at all. Barely even needed the wax/ grease remover (which frankly works amazing for removing sticker residue).