sentences:  Rosberg managed Nissan's factory program in 1997 and 1998, with a pair of Nissan Primeras for Roland Asch and Sascha Maassen.Asch was the highest ranked Nissan driver, finishing eighth in the 1997 championship.1998 was no different; Asch again finished eighth overall, and Maassen's replacement, Michael Krumm, finished ninth.