The Tesla battery modules are about the same size as the LG chem batteries that some use. You just add as many as budget or space permit
The Formula E race series uses all electric cars. It looks like they have experimented with lots of different transmissions/drivetrains. This video is good for a starter but doesn’t touch on that:
This site is outdated now but covers some of the drivetrain history:
https://www.fiaformulae.com/en/news/2016/october/insight-how-the-cars-have-changed/
I believe I have the slowest (but most efficient) Model 3 there is, and I’m glad it’s not faster. Can’t believe there aren’t more accidents with them.
If you pull the engine out of it, there’s a lot of room to stuff hardware into an MR2, even if you don’t use the frunk.
As to how big they are, each battery module is composed of an array of cells about the size of a AA battery. They’re packed standing vertically, with something like 440 cells per battery module. The module is about a foot wide by 2 feet long by 3 inches high. There are 16 modules in a P85