I'm working on a design for a TV mount, and this came up. Vizio shares the dimensions of their TV, the dimensions of the VESA mount, but not the location of the VESA mount. Not helpful if you want to do any better than "eyeball it".
I took one of their pictures, overlaid some dimensions, and came up with hopefully a fairly accurate guess for the actual VESA 200x200 location.
Obviously this isn't perfect, but it should be close: The top of the VESA holes is approximately 235mm (9.25") from the top edge of the TV. See photo!
Note: I used the nominal dimensions of the TV and the VESA mount per the user manual. Clearly the image isn't perfect since the nominal dimensions don't line up with the image, but I would guess this technique is good for +/- 5mm or so... assuming this is actually an image of the e43 and not some stock image they use for all e-series tv's. I cannot account for that. (This is for a client and I don't personally have this TV in my possession, and I need to do my design without being able to actually measure this dimension directly.)