In the early 2000s there was an Italian company in Emilia Romagna doing these combustion → electric makeovers on an industrial scale. Their average customers where municipalities and large businesses (airports, for example) converting their existing fleet of ICE cars into electric vehicles.
They lost most of their businesses around 2012 when Italy passed a bill making all these converted cars not roadworthy without an explicit permit from the original manufacturer, permits that very rarely where granted. (That law got partially overturned in 2017, but the FUD and the chilling effect remain today.)
They lost most of their businesses around 2012 when Italy passed a bill making all these converted cars not roadworthy without an explicit permit from the original manufacturer, permits that very rarely where granted. (That law got partially overturned in 2017, but the FUD and the chilling effect remain today.)
Source: a friend of mine being laid off by that firm in 2012 + http://mondoelettrico.blogspot.com/search?q=retrofit