Well that all depends if the Universe does have spatial boundaries. If it does, then moving at the speed of light will make one end of the Universe right next tothe other, from your perspective. In other words the Universe would be two dimensional. This is because of length contraction. THough suprisingly the car would be longer than the Universe, since its length is not affected.
Actually, i just thought, if the UNiverse had no spatial boundaries, then its length would be infinte. Apllying that to the length contraction formula gives:
L'=inf*0
The length of the Universe would then be infinte multiplied by zero.
