At the end of the 1990s, several changes made to the Thomas product line were related to its purchase by Freightliner. At the end of 1998 production, Navistar ended its chassis production for the Vista; as the Vista body was developed solely for its chassis, Thomas discontinued the model line. While Freightliner did not purchase the Ford medium-duty truck range or the school bus chassis derived from it, Ford ended production of the latter after 1998. Consequently, from 1999 onward, the Saf-T-Liner Conventional was limited to Navistar or Freightliner chassis (along with AmTran/Ward, Carpenter, and Wayne, the last General Motors chassis for a Thomas bus was produced in 1991).