Yes the back cover can be replaced,I changed mine last month because I scratched on the garage wall
Its just a matter of unclipping the mirror glass
and taking out 3 screws
there is a clip in the bottom corner,just pull and it will come of,dont worry if it breaks and then just replace in reverse
Yes it can be ordered from a lexus dealer because I already have
They are already painted and cost about £21.00+VAT
Best Wishes
Chris
[Edited on 12-3-2002 by Chris Shipley]