If I am correct you can only use vehicles with a manual gearbox. When I looked at the EV Conversions [or whatever they are called] they only use manuals. I seem to remember emailing them, for the crack, and they said that they couldn't do an auto P38.
I think that the reason is that the gearbox, in a manual, is locked into gear, maybe 3rd and the huge torque of the motor just drives the vehicle forward.
I don't know much about these conversions, but there are a lot of ev conversions in the States, as you can buy all the parts of the shelf over there.
That'll be if they connect the motor to the input shaft of the gearbox though. A few months ago I watched a TV programme (something like Vintage Voltage) where they converted a Landrover to EV using Tesla bits, they didn't use the original gearbox, instead fitted the Tesla drivetrain rotated 90 degrees under the middle of the LR so the output that would usually drive the LHR wheel turned the front diff and output that would usually drive the RHR wheel drove the rear diff. Then they realised this arrangement meant front wheels would go backwards while rear wheels went forwards so they had to have a special diff (or might have been output from the Tesla gear) built that turned the rear wheels in the opposite direction to normal for direction of the prop shaft. The diff / gear alone cost something like £5 to have made up. I might have tried mounting the diff upside down first lol (mind you the LR will have had a live axle so probably not possible).
I suppose if we're talking £245k cars it wouldn't be a big deal to remove a slush box to fit a manual box as part of the conversion process.
The engineering firm that made the diff (or adapted the Tesla drive) designed, built and delivered the parts very quickly, got to wonder how long the process would have taken if they didn't know it was going to be featured on TV.