Well-known to viewers of BBC Top Gear, Sabine Schmitz is preparing to make her Silverstone Classic (26-28 July) debut racing a 220mph Porsche 962 in one of the massive events thrilling races for Group C prototypes.The 44-year-old German first came to fame as the fastest taxi driver in the world, a title she gained for driving passengers around the full 12.9-mile Nrburgring Nordschleife circuit at very high speeds.Over the past decade Schmitz has made regular appearances on Top Gear most memorably when claiming all she needed was a Transit van to beat Jeremy Clarksons best lap time around the fearsome Nordschleife in a Jaguar S-type diesel. It was a challenge she only just failed to master in a later show.As well as being a television personality both in the UK and Germany, Schmitz is also a notable racing driver. Indeed, she was the first woman to taste victory in a major 24-hour race when winning the Nrburgring 24 Hours in 1996 a feat she repeated the following year, too.At the Silverstone Classic, Schmitz will be sharing a Porsche 962 with Klaus Abbelen in the two spectacular showdowns for Group C prototypes that raced at Le Mans in the Eighties. The Porsche 962 is such great car for the purists I just love driving it, she said. Silverstone is the Mecca for all petrolheads and, with all the downforce in the fast sections, racing the 962 is going to be a fantastic experience if a little painful on the poor old neck muscles! Its going to be an incredible feeling to be racing against so many wonderful cars from that period, confirmed Abbelen. For us to be part of something so special is just going to be amazing. We cant wait.The two Group C races are now firmly established among the major highlights at the Silverstone Classic, notably the spectacular showdown at dusk on Saturday evening. Every year the entry seems to get stronger and more competitive.Incredibly this years grid will include no fewer than six Porsche 962s with ex-F2 racer Herve Regout likely to be the pacesetter. Others to look out for are Japanese speedster Katsu Kubota in his Nissan R90C a winner at the 2011 Classic plus the fire-breathing 1989 Mercedes C11 Silver Arrow shared by Gareth Evans and triple FIA Thoroughbred Grand Prix champion Bob Berridge.Nic Minassian debuting the worlds sole surviving Jaguar XJR-14, though, will take a lot of beating. As a member of Peugeot factory team, the British-based Frenchman has two Le Mans podiums to his name in 2008 and 2011 and the Ross Brawn-designed purple XJR-14 won the FIA World Sportscar Championship in 1991 when piloted by the likes of Martin Brundle and Derek Warwick.Indeed the evocative Group C field is truly representative of the era with Jaguar XJR8/9, Martini Lancia LC2s, Spices galore, a Swiss-built Cheetah and the Australian Veskanda-Chevrolet all in the mix.  This years two Group C race have all the ingredients to be the most exciting yet, said Nick Wigley, Event Director. We have all the most competitive cars and drivers from past years plus the added thrill of Sabine in the 962 and Nic in the incredible XJR-14 which is probably the ultimate Group C racer. The sights and sounds of these fabulous cars racing into the sunset on Saturday evening is going to be very special.Those wanting to catch what promises to be two epic Group C battles at the unmissable Silverstone Classic must buy tickets in advance. In keeping with the popular events widely acclaimed access all areas policy, tickets include free entrance to all the special classic car displays, both National and Wing racing paddocks and pit complexes, trackside grandstands, live music concerts on Friday and Saturday evenings plus a host of other entertainment for all ages and interests. Adult admittance is from just 35 (plus fees) and considerable savings are on offer for those festival goers spending the full weekend at Silverstone. Full details can be found on the official www.silverstoneclassic.com website.