Basically, I am going Portsmouth university after taking a gap year. In that gap year I was thinking of working full time and buying a car, I am from London, so I would like to come home quite often. but on second thoughts, I don't know if it is a good idea.
Check the average price of a round trip train journey and then the average petrol cost of the journey for a starter car. I have a car but it's cheaper to get the train to and from where I'd like to go (3 hrs in the car). Of course you've got to take into account insurance costs but comparing single journeys, check out trains.
Portsmouth is actually an island - one road on, one road off. Parking is an utter nightmare and costs a fortune. You don't need a car because everything is either close enough to walk or there's a bus.