Yes Ford own Mazda (since the mid '70's [1]), but AIUI it was the Japanese design people behind what became the Mondeo 'floor pan', remember that the Mondeo was one of the first designs that used Fords company wide linked CAD system and that the car was designed from scratch in about a month.
[1] Ford bought something like a 51 percent share when Mazda nearly went belly up due to the rotor tip seals fiasco of the RX3 rotary engine.