Document presents technical challenges to defining retrofit kit types for electric conversion and approval processes. Identifies that retrofit kit type perimeter depends on the regulation considered, with different requirements across UN R10, R13, R100, R85, R138, WLTP, R79, R39, R51, R89, R121, and R122. Presents testing challenges at vehicle, component, and EPRS levels, noting that testing a kit type not installed on a vehicle is impossible to account for all impacts on the vehicle.