The best way of deflating this type of comment is to ignore it, join in the joke, or take him down your favourite b road in it.
People who make these comments are the same brigade who tell you that they drove from Cornwall to Newcastle and back again overnight, then answered 300 emails at 3 oc in the morning and have arguments with other similar people as to who has the largest wedding equipment..... you can rise imperiously above it.
My main car is a 1992 Toyota Corolla 1.3 auto - I just let the comments go over my head as they all race past.