Special device can intercept the code that the key transmits and can also replace the key’s transmitting capabilities. Chip manufacturer NXP confirms the vulnerability.
Dutch language news article:
http://www.nu.nl/internet/2878918/onderzoekers-hacken-chip-in-autosleutel.html
Brands and models:
http://nieuwsuur.nl/documenten/autolijst_1_1.pdf