Subaru E-Boxer; small electric motor mounted in the transmission, with a small battery pack in the trunk:
Electric motor output:
Power: 13.4 hp (14 PS; 10 kW)
Torque: 48.0 lb⋅ft (65 N⋅m; 7 kg⋅m)
Sounds perfect. But it adds 110kg to the forester [emoji53], the 86 can probably get away with a much smaller battery and weaker motor controller though.
https://en.m.wikipedia.org/wiki/Subaru_FB_engine