Didn't think about resale issues....
I actually modified and installed one of the convex interior rear view mirrors used in the race cars etc... Modified the stock base and neck and made a new mount that allows me to push the mirror up pretty high and still have a great view out the back.... Works great and I can see out the back glass and the rear quarter windows on the mirror
...... The image is alittle different than a flat mirror by the view angle is huge.... Not enough to replace having side mirrors but now can see the entire back seat... So I can scream at the kids more effectively