After installing the M400 gearbox and the motor in the car and modifying the tunnel, I can start building the motor mounts. Die original Volvo Amazon motor mounts are too big because the Siemens motor is wider than the B20.
Perhaps mounts from a Volvo 140, 240, 740 of even a Penta (boat) can be handy combined with a frame at the sides of the motor to connect them to. That will however require quite some measuring and “trial and error”.
Therefor I started with my initial idea for the mount. A 10mm thick steel plate mounted on the front side of the motor with ‘flaps’ on which the motor rubbers can be mounted. First I created a mockup of wood to get a first idea of the angles and distances.
Next created a prototype using steel.
Quite nice for a first attempt. Must be mounted a little higher because the free space between the subframe is only 5 mm.
In the end it will be build using thicker material of course. For the record, the motor weighs 90 kg and can deliver 300 Nm of torque.
Update
In the meantime I have taken some measurements from the first steel prototype and aligned some angles and lengths. Building on that I created a new prototype.
While test fitting in the car it turned out that the “flaps” are not symmetrical. There is a 10 mm difference. After checking it turned out the original B20 left and right motor mounts are different too and also the mounts on the subframe are not centered. Something you would not easily notice. Now the motor is level, 10 mm of clearance at the motor while on his weight.
Using this prototype and the 
CAD drawing of the Siemens 1PV5135 motor I am going to have it fabricated using a 8 to 10 mm steel panel. Similar to how New Electric did it in their Jeep CJ-5 conversion.
In that case the ‘flaps’ look even longer and horizontal. Building on that my design will be able to handle the weight and torque as well.
Update 2
I have extended the prototype to make it representative for the final form factor.
Added some ribs and larger contact areas for the rubbers.
Update 3
I also created a supporting cardboard model to see how we can fold/create it from one piece as much as possible.
So this is the kind of shape that needs to be lasercut.
The outer flap can be bend and only the inner rib needs to be welded. Next week contact some workshops to discuss planning and costs.
