The new 1400 Guzzi Cali engine would be a good choice and with the bike based transmission would make a much lighter car. The Moto Guzzi is a lovely engine. The Triking has a very compact reverse box after the sequential bike box and it seems to work well. The JZR installation was not so clever and sorted as Triking but the kit price was much less. That said the engine and gearbox side of things are not the parts causing too many problems and the S&S engine suits the M3W well.
