Liz, I've found another possibility for your Mercedes. The 1/43 resin kit company BBR released the 1999 car. Grand Prix Models, who over the years have enjoyed a long and profitable association with my credit card, certainly list the BBR flying Merc on their database as still current. The serials are as follows.
BBR Kit
BBP214 Mark Webber's car, which crashed in practice
BBP215 Peter Dumbreck's car, which flipped during the race. (GPM's kit database describes this as "sponsored by Lufthansa")
http://www.grandprixmodels.co.uk should get you there - but be warned, temptation is a dangerous thing.