I've been reading up on the 2022 Season of the World Rally Championship and have learned that for 2022, they required that all Rally1 teams incorporate a hybrid "boost" system.
From wiki: "The hybrid electric power system is supplied to all teams by a third party, Compact Dynamics, incorporating a battery supplied by Kreisel Electric. It is used to power the cars in 100% electric zones on liaison sections as set in the rally roadbook by the rally organizer. On the special stages it also provides a boost of up to 100 KW or 134 hp alongside the combustion engine and recuperates kinetic energy under braking. The driver will have three options to choose from to deploy the boost, with a further three options to choose on how to recuperate energy under braking. The driver must set these options before a special stage and are not able to choose when to deploy the electric boost within the stage. The hybrid electric system adds an extra 84kg to the cars gross weight and due to its 750-volts the cars will wear HY identification, with white letters on a red background, on the door panel. Crews are also required to carry high voltage gloves to use in the event of an issue."
Basically, it's this fully-contained box of a battery, inverter, and motor that sits inline with the rear driveshaft.
"In full electric mode the car has a range of 20km (12 miles), while its 3.9KWH battery, operating up to 750 volts, can be plugged in and recharged in the service park within 30 minutes."
This is interesting, especially because of how it potentially translates to road cars.
Imagine a small AWD car like a Mazda 3. Throw in a 178hp Skyactiv-X motor that'll get nearly 50mpg. Add in a plug-in hybrid system similar to that use in a Rally1 car, but with a better hidden battery. That'd give you 300hp on tap, but for errands you'd either run it all electric, and for longer trips you'd have the high-efficiency gas motor. Give it a trans that automatic most of the time, but can be operated like a like a center-mount lever sequential and it'd be a sensible rally car for daily driving.
