Note that Stewart, who otherwise always drives his regular car (white, with black roof), this once uses a different car (white, with white roof) when driving to the space institute - although he obviously had no way of knowing that the villains would cause the car to wreck and explode on the way back.
(In the hospital, after Stewart's car wrecked)
Annabelle: Someone opened a cylindar of liquid oxygen and hid it in the boot of his car!
Jason: Liquid oxygen? Neat?
Jason: Stewart must be very, very drunk.
Annabelle: Exactly. He was so high he could've floated away!
Jason: Sounds like a good way to start Mark Caine. I must remember that.
Annabelle: There's nothing "foolproof" about a dead man, four spacesuits, and a set of magnetic locks.
Jason: That's your trouble: being married to a computer, no imagination.
Jason: Keep your fingers crossed, and let me do the talking for a change.
Stewart: (after Jason leaves) Could we stop him?