First you need to speak to your IP and ask their permission to take on credit for a new car.
If they agree, you can then look at buying. Dunctons are specialists in dealing with people with low credit scores but have a very high APR. Borrowing from a family member or close friend may be a better option if that avenue's open to you.
If they don't agree to borrowing to buy a car, they may agree to you leasing a car. Again, Duncton can help as you will find it difficult in the mainstream market.
The other option is a payment break to save for a new car - but this would usually only be £1000 or so.
Duncton do come recommended, but the downside is that you need a fair size deposit as well as the APR being high.
It might be worth approaching a family member to see if they can help you out.
Sharing from experiences of dealing with debt
The greatness of a man is not in how much wealth he acquires, but in his integrity and his ability to affect those around him positively.
Bob Marley. http://kallis3.blogs.iva.co.uk