Technical Is there a modern semi-automatic (ie Fluid Drive) trans?

Citroen do everything with hydraulics and vacuum not with electromagnets.
There was the Cotal transmission that was electromagnetic with a bunch of small gears, from the 30's to early 50's mostly on luxury vehicles, it has been adapted to some Traction but never was standard equipment.

 

Renault used the Ferlec clutch in the Dauphine(late 50's early 60's).
This was an eltro-magnetic clutch switched by a micro switch under the gearlever.
There was a switch on the dashboard to allow you to clutch start the car.
The clutches activation was via a rheostat attached to the throttle linkage that increased the voltage as revs rose.
Worked quite well, but I replaced the one in my first car with a full manual.
Porsche also had the Sportmatic in 1974 to around 1978 for those who couldn't use a real clutch. If you drove one all the other Porsche owners laughed at you. Doubt any still exist.