I believe that if you have the drivers side and your internal rear view mirror, your good to go, legally. I have had the opposite challenge to what you want to do. I have 3 Honda's which I've added passenger side mirrors to, but since I couldn't find one at the junk yard, I have ended up taking one off of a similar vehicle and modifying it to make it fit.
On all three of mine, the mirror mounting holes were covered by a plastic plate which had 3 screw standoffs in it. If you check at a junk yard, maybe you can find the right hand plug, on a car from your year. Mine are an 87, 89 and 91 Honda.
Personally, I'd leave it on. The safety enhancement to my driving is worth far more than the minimal amount of fuel savings I might have had. FWIW
i want to take it out because i never use my side mirrors, i just aim them away and to the ground when i drive because i drive alot at night, and i always get blinded by otehr headlights when im on the road. i just look at my rear view mirror, then at my blind spot, then i signal and change lanes.
My wife's Chrysler van has what appears to be a piece of film type window tint added to it. It is sort of gold/honey color of stuff. It is a little different to get used to, but it seems to really help with the lights in the mirror stuff at night.
on my 1983 civic hatch, '84 civic hatch, '85 crx, and '92 civic vx, non of them came stock with a passenger side view mirror, my civic vx does have one tho, but just like a number of other things, it was a factory, or maybe a dealer option, and cost extra, the block off plate uses the same holse as the mirror, however most of the sedans use a differnt mirror I belive, and I think it was just the base modle civics, and the fuel efficent modles that didn't come with a mirror stock... so the block off plate might not be a perfect fit, but I can't say for sure.
also, most states require that you have two useable mirrors, so if you are towing a trailer, or have something blocking your rear window, you are suposed to have a passenger side mirror, I personaly don't use it much either, partly because this is the first car I've owned that had one and I'm just used to it not being there.