I believe you're right. Hybrids and electric cars are excluded from import tax. However, if it's a regular car, you pay a percent of the car's original sale value based on how much it pollutes, more or less (it's more complicated than that, but that's the basic idea).
*Exception to the exception: if the car is worth more than €16,000 (used) or €20,000 (new) you still have to pay a luxury tax.
If it's coming from outside the EU, there are a LOT more taxes, that's a totally separate issue.
i found this last night .
europa.eu/rapid/pressReleasesAction.do?reference=IP%2F12%2F349&format=HTML&aged=0&language=EN&guiLanguage=en]EUROPA - Press Releases - Commission slashes unnecessary burden for registering a car in another Member State