yeh, when i removed my doors i welded a small stainless steel tab on the stainless light bar just above where the normal mirror would mount on the door, and then bolted a stainless steel motorcycle mirror to the tab...seams to work ok....its mainly just there to make it legal though...
and another thing...i was told that u couldnt legaly drive around with the doors off on any wrangler with a build date after the 6th month 97...(when the side intrusion laws were introduced)....just a thought