Dave Weise, Greg Padginton

Dave Weise — Dave Weise joined Mattel in 1994, creating castings for Hot Wheels and Matchbox. He moved to Matchbox as a designer in 2006, where he rose to die-cast design manager, and retired in 2015. The Matchbox wiki does not list the cars he designed or his education.

Greg Padginton — Gregory John Padginton was a Hot Wheels designer at Mattel from 1992 to 2008. Before that, he was an artist; today he works for himself, as an independent contractor. The wiki does not explicitly attribute any models to him (there are images with his name in the caption, such as Ratbomb, which does not prove authorship).