I saw the Elise mirror plinths on Wilberts Speedster. The big advantage of the Elise plinths are that they are wider, which increases rear visability a lot.
The nice thing is, that they also are pretty cheap, round EUR 12 a piece. They are a bit heavier though, the original plinths are hollow, the Eilse's are massive. Ofcourse they arrive unpainted, so they first need some painting, afterwards they look like this:

As you can see with the original plinths, they bottom curves wit the door. Unfortunatly I wasn't smart enough to check this before they went off to the painter.

Fortuantly it was not too late and I could modify the plinths without damaging the paint. But to get them to fit right, I first had to remove the original plinths. They are attached with 3 bolts. Make sure you don't drop them into the door, it's a lot of work to get them out again (and I know about it).

When you put the original and the Elise plinth next to eachother you can see the height difference.

After modifing the plinth so it nicely meets the door, the mirror can be attached to the plinth. This only requires 1 bold. Make sure you don't damage the pint though.

The plinth can then be placed back on the door. Try to make sure again you don't drop the bolts in the door.

The hole where the bolt goes through can be covered up with a round piece of tape, just like on the Elise.