The research group of Prof. Capkun has demonstrated that the wireless proximity-based entry systems widely used in modern cars are vulnerable to so called relay attacks. In a relay attack, the adversary relays signals to the wireless opening device that is expected to by in near proximity of the car, but actually resides a long distance away from the car.
Such problems can be addressed with more secure proximity-based wireless systems that leverage so called distance-bouding protocols. In a distance-bounding protocol highly precise timing measurements are used to verify that the wireless opening device truly is in the close proximity of the car. A ZISC spinoff company 3DB Technologies is at the moment developing more secure entry systems for the car industry.
Zurich-based newspaper Tages Anzeiger covered the research of Prof. Capkun. Read the full article (in German) at: http://www.tagesanzeiger.ch/wissen/technik/clever-gegen-autoknacker/story/30770109
Further details about secure proximity verification are available in a related technical paper.