vpn on 2811 with overlapping networks and all natting on one side

Hi,

I have a vpn setup with the same private networks at both sides.
We don't control the other vpn peer and my customer wants to do all
the natting on his side.
With a pix/asa it is possible to nat the source and destination on one
side of a vpn setup (bi-directional translation):
http://www.cisco.com/warp/public/707/vpn_pix_private.html

Has someone done the same setup with a router (2811 with ADVSECURITY)?

Br.
Robby
.