Plug-in hybrids are selling well, particularly in large European markets where generous government incentives slash the cars' high starting prices.
Consumers like them because it's possible to drive electric, as long as the battery is charged, without range anxiety because the combustion engine and a full tank of fuel are there as a backup.
Automakers love them because plug-in hybrids help the companies reach their CO2 targets, avoiding big fines from EU regulators.