Gonna revive this dead thread for a bit. Have been pondering a hidden winch on my wag for several years. Don't want any visible external modifications other than a hawse fairlead on the front bumper, which will be covered by the front plate.
My thoughts would be to notch the front cross member, maybe 1 1/2" upwards and about 18" wide (after moving the brake line out of the way so as to not damage it).
The steering box would prevent a full sized unit unless it was offset. I'm looking at the overpriced 9.0rc from Warn due to compact footprint.
With the cross member notched, a winch plate would be welded to this notch, centered, with equal overhang front and rear.
This would allow the bolts plenty of room to be tightened from above (winch upside down and components clocked as needed for drainage). The winch plate would be strengthened by a lip (probably 1 1/2") on the 4 sides. To further address crossmember strength, there would be gussets from the plate angled downward to the lower frame lip. The gussets would also be welded to the crossmember.
Pictures are worth 1000 words, so a quick paint program drawing:
The rubber air dam would completely hide the winch from sight. I would probably remote mount the control box on a custom bracket that attaches to one of the fog light mounts for simplicity and ease of use.
Thoughts and critiques welcome.