I'm in the no camp. I can back up just fine without a passenger mirror, just takes practice, or if you park it in a certain spot a certain way every time, a few garage tricks can help.

Cutting (well... drilling) an original, adding weight (yes! LOTS OV WEIGHT!!! shut up), complexity, wind resistance. Possibly messing nice paint. And basically adding just another thing to go wrong or break. Vandal target. Home for extremely angry wasps. Spending money you could rather spend on beer or metal CD's. And how many hours ov your precious life will you waste getting this right? Think ov the kids. Maybe you dont like your kids? I dont know. You could use that time re-watching the season 2 finale ov Vikings. That will add more to the value ov your life than a silly (and heavy) mirror.

Strippers rule. I mean cars... you pervs...

Just DONT DO IT. For the love ov the Gods... dont do it.