I want to buy a set of carbon fiber Spoon style mirrors from JDM Carboy (or something similar) and modify or make new bases to fit them on a BMW.

My question is, since these mirrors are 2-piece (the mirror and the base separate), how flat is the back of the mirror where it mates to the mounting plate? I want to be able to mate them to flat bases without having any gaps between the mirror and the base, but it looks like there could be a slight curvature to the base of the mirror where it meets the plate judging by this pic:

 

Those mirrors are pretty universal (that's why they make them for everything out there now), I don't think you'd have much of a problem matting them with any base you want. They are curved a bit though so they stick out from the car correctly, it won't be like a perfect square or anything.

 

Thanks man. I figured they weren't perfectly flat, and the mounting plates I have cooked up in my mind would be so I feel like there would be a little gap. But from the picture, it looks like the size and proportions might be similar enough that I could cut the bases that come with the mirrors down and then add some new attachment points...

 

buy some cheap *** ones and test fit, cant be off by much

 

I've personally never detached some from the base before, they seem to bolt in from behind the mirror, so you'd have to adjust it out of the way and some how unbolt it from the inside. At least that's how my fakes have been. But if you can figure that out and have another base it should fit ok I'd think. I don't know how much room there would be for shaving any material off to make them fit better but maybe a little to play with. They are much cheaper on ebay, and you can find them with blue tinted mirrors that fit perfectly inside the shape which look like the real things. Don't get them from JDMSH!T or anything, they are way over priced and the quality sucks.