Strugglerzinc the difference between cube 3 and normal cube is that it has extra seats to the back so it can hold 7 adults comfortably, plus it is a little longer to make room for that extra seat, couple of other things are different to due to the extra weight the cube 3 will be carrying such as bigger brakes and sturdier suspension.
Vega with regard to performance, it has a 1.4 engine that is very torquie so even though it carries that many people you can still cruise at 120k/h on the highway without trouble. when i am alone and coming to work in pos at 4:30 am i have clocked 160 k/h with o/d off, I don't drive so with other people in the car
