First of all think to yourself - do you really need a car at uni? It's an expense of 200-250 per month for most people when factoring in insurance, tax, petrol.
I would
really highly recommend going to university without a car for at least the first few months to get used to the surroundings etc.
This is what I did - I waited until christmas, realised I had the funds and space to park a car (I get a permit here in Swansea) so brought a car back then.
A car can make things super fun especially in a remote town like Swansea - but in Hull you won't need a car except to get back home to London. I suppose you'll maybe be doing this once a month at most - so a train ticket (Friday evening to sunday evening Hull to London is £60 return without a railcard if you book in advance) or a coach ticket (£40 return) would work out nearly twice as cheap as paying for a month of parking, let alone the cost of petrol (A 45mpg car will cost you £67.14 to get to Hull and back from London Brixton in petrol alone).
Cars are bloody expensive especially as a student, I only have one as I am doing an automotive design course and it is my hobby.
If after all my advice you still want to have a car at uni..... try local supermarkets to see if they have permits going, I know Sainsburys often does them. £70 a week here I believe.
Or you could start uni and in the first few months of living there ask other people in second or third years where they park their cars.