Carivo

A car advertised in one EU country and registered in another almost never costs what the advert says.

A real example — Netherlands to Spain

Asking price €9,500
Registration tax (Spain) €560
Transport, Netherlands → Spain €1,100

On your driveway €11,160

The advert shows the top line. Carivo shows the bottom one — next to every real listing, calculated for wherever you're actually registering the car.