I have the 2nd gen MES 40. I did order the Amazon cover. It did in fact not fit. I took it to a car upholstery shop and had him split it all the way around on the long side , which would be the front, top, back. I had him sew in a piece to widen it 5". Fits now and looks good.
One problem! The back two top edges have sharp corners. I kept the 4 corner protectors that came with the shipping package. I put a bead of silicone all around close to the outside edge and mounted them on the back top edges. No more sharp points to cut the fabric. Will work on any MES!!
Cost me $20.