A survey allegedly created by Sony appears to hint at the existence of a version of Gran Turismo for PlayStation Vita, or at least the consideration of one.
The survey asked participants to indicate how interested they would be in a Vita version and whether the chance of a PS3 version discount would tempt them into a purchase. It also mentions a PlayStation Plus offer that would see purchasers gain access to the PS3 version of the game if they bought it on Vita and vice versa.
Screenshots of the survey can be found via the source link below.
Does a Vita version of Gran Turismo interest you?