[ErroneousBosh]

I'm quite keen to get the battery and motor out of a scrap Leaf to fit to something.

The motor package from a Leaf is about 90kg so probably in the same ballpark as the fuel tank, rear axle, and gearbox. You'd then need to get a lighter battery because a Leaf's battery is about 350kg, or twice the weight of an MX5's engine.

There would be a lot of surgery involved on the back end but since it's a subframe with the diff in the middle you're halfway there.

And for once, the project car's totally rotten boot floor won't be a problem because you're cutting all that away anyway!