[AXMonster]

I've had an idea of a home made hybrid. It will not be greatly powerful, and only be an assist motor for a hybrid conversion using the 5th gear extension on the gearbox's mainshaft (as I think the Metro also has?).
The mainshaft rotates continuously and feeds power through the differential directly, so this would be a gearless motor system that would be independant of the engine and gears.

There's a steel pan extension to the side of the gearbox that houses the 5th gear. It would be possible to add a drive to the gearbox main shaft through this pan using a belt drive system, and locate the motor above the gearbox.
A belt drive like a cam belt system would do the job.

The shaft ends with a nut holding the 5th gear cog on. My theory is to replace this with a threaded driveshaft that can be torqued onto the shaft as the nut is currently, then dowelled in place to ensure it does not move. This would then serve as the mating shaft for the toothed drivewheel driven by the motor that is located above it.
The steel pan will need to have a shaft seal on it the same as a crank oil seal, but I don't see this as a big job.

First diagram below shows the gearbox
Second shows the approximate positions of the 5th gear & shafts
Third shows where the motor would locate above the gearbox, next to the engine.

Any comments??