Also underway at Volkswagen's Braunschweig R&D facilities in Northern Germany is a hybrid version of the next-generation Touareg. VW intends all future models to have the hybrid option. "Future VW models will fundamentally also be constructed with hybrid concepts," VW head of development Ulrich Hackenberg told "Automobilwoche" in an interview. Hackenberg mentioned that the car based on the Up! concept seen at Frankfurt Motor Show, as well as all future models, could be offered with either full or partial hybrid options. The rear-engine up! will go into production in 2011. Nothing has been said about plug-in hybrid options. Volkswagen announced at the 2010 Geneva Motor Show the launch of the 2012 Touareg Hybrid, scheduled for 2011. VW also announced plans to introduce diesel-electric hybrid versions of its most popular models in 2012, beginning with the new Jetta, followed by the Golf Hybrid in 2013 together with hybrid versions of the Passat. In 2012, the Volkswagen Jetta Hybrid set the world record to become the fastest hybrid car at 187 mph. In November 2009, Volkswagen announced it has hired Karl-Thomas Neumann as its group chief officer for electric traction. VW's Chief of research, Jürgen Leohold, said in 2010 the company has concluded hydrogen fuel-cell cars are not a viable option.  , the Volkswagen Group offers for retails customers nine plug-in electric cars, of which, three are all-electric cars: the Volkswagen e-Up!, e-Golf and Audi R8 e-tron, and six are plug-in hybrids: the Volkswagen Golf GTE, Passat GTE, Audi A3 Sportback e-tron, Q7 e-tron quattro, Porsche Panamera S E-Hybrid and Cayenne S E-Hybrid. Also two limited production plug-in hybrids were manufactured beginning in 2013, the Volkswagen XL1 (250 units) and the Porsche 918 Spyder (918 units). Total cumulative sales of all Volkswagen brand electrified cars since the start of their respective production is expected to reach about 103,000 by the end of 2016. In order to comply with increasingly strict carbon dioxide emission limits in major markets, the VW Group expects to sell about one million all-electric and plug-in hybrid vehicles a year worldwide by 2025. The Group plans to expand its plug-in range with 20 new pure electric and plug-in hybrid cars, including two cars to compete with Tesla Motors, the Porsche Mission E all-electric car and the Audi e-tron quattro, which is expected to become the brand's first mass-production electric vehicle.