In the Safari line, the SE (Special Edition) models are those with aluminum interior skins. It's an option that costs about $5k.
Generally speaking, when comparing the aluminum to the vinyl interiors, the aluminum interior will be cooler in cold weather and warmer in hot weather. The difference is mostly due to the insulating properties of the two materials and partly due to the difference in windows between the SE and non-SE models.
Hope this helps clarify things a bit.
Mike Young & Rosemary Nelson
Bowlus Road Chief "Endymion"
BMW X3 xDrive 28D